diff --git a/CLAUDE.md b/CLAUDE.md
index 29f527d..8695d31 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -6,9 +6,9 @@
 
 - **프로젝트 타입**: react-ts (모노레포)
 - **Frontend**: React 19 + Vite 7 + TypeScript 5.9 + Tailwind CSS 3
-- **Backend**: Express 4 + better-sqlite3 + TypeScript
+- **Backend**: Express 4 + PostgreSQL (pg) + TypeScript
 - **상태관리**: Zustand (클라이언트), TanStack Query (서버)
-- **지도**: Leaflet, OpenLayers
+- **지도**: Leaflet
 - **실시간**: Socket.IO
 
 ## 빌드/실행
@@ -70,7 +70,7 @@ wing/
 │       ├── audit/             감사 로그
 │       ├── routes/            레이어, 시뮬레이션
 │       ├── middleware/        보안 (입력 살균, rate-limit)
-│       └── db/                DB 연결 (PostgreSQL, SQLite)
+│       └── db/                DB 연결 (PostgreSQL: wing, wing_auth)
 ├── database/                  SQL 초기화 스크립트
 ├── docs/                      개발 문서 (README, 가이드, 변경이력)
 ├── .claude/                   팀 워크플로우 (rules, skills, scripts)
diff --git a/README.md b/README.md
index 7832a3e..4fac801 100644
--- a/README.md
+++ b/README.md
@@ -126,7 +126,7 @@ wing/
 | 영역 | 기술 |
 |------|------|
 | Frontend | React 19, Vite 7, TypeScript 5.9, Tailwind CSS 3 |
-| Backend | Express 4, TypeScript, better-sqlite3 (레이어), pg (인증) |
+| Backend | Express 4, TypeScript, PostgreSQL (pg) |
 | 상태 관리 | Zustand (클라이언트), TanStack Query (서버) |
 | 지도 | Leaflet, OpenLayers |
 | 실시간 | Socket.IO |
diff --git a/backend/package-lock.json b/backend/package-lock.json
index 761c796..a3d5138 100755
--- a/backend/package-lock.json
+++ b/backend/package-lock.json
@@ -9,7 +9,6 @@
       "version": "1.0.0",
       "dependencies": {
         "bcrypt": "^6.0.0",
-        "better-sqlite3": "^11.9.1",
         "cookie-parser": "^1.4.7",
         "cors": "^2.8.5",
         "dotenv": "^17.3.1",
@@ -22,7 +21,6 @@
       },
       "devDependencies": {
         "@types/bcrypt": "^6.0.0",
-        "@types/better-sqlite3": "^7.6.12",
         "@types/cookie-parser": "^1.4.10",
         "@types/cors": "^2.8.17",
         "@types/express": "^5.0.0",
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-      "resolved": "https://registry.npmjs.org/@types/better-sqlite3/-/better-sqlite3-7.6.13.tgz",
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-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
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-      }
-    },
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@@ -773,17 +761,6 @@
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-      "hasInstallScript": true,
-      "license": "MIT",
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-      "dependencies": {
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-        "inherits": "^2.0.4",
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@@ -873,30 +830,6 @@
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-      "funding": [
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-          "type": "github",
-          "url": "https://github.com/sponsors/feross"
-        },
-        {
-          "type": "patreon",
-          "url": "https://www.patreon.com/feross"
-        },
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-          "type": "consulting",
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@@ -941,12 +874,6 @@
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@@ -1489,12 +1359,6 @@
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@@ -1598,12 +1462,6 @@
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-      "version": "1.2.8",
-      "resolved": "https://registry.npmjs.org/rc/-/rc-1.2.8.tgz",
-      "integrity": "sha512-y3bGgqKj3QBdxLbLkomlohkvsA8gdAiUQlSBJnBhfn+BPxg4bc62d8TcBW15wavDfgexCgccckhcZvywyQYPOw==",
-      "license": "(BSD-2-Clause OR MIT OR Apache-2.0)",
-      "dependencies": {
-        "deep-extend": "^0.6.0",
-        "ini": "~1.3.0",
-        "minimist": "^1.2.0",
-        "strip-json-comments": "~2.0.1"
-      },
-      "bin": {
-        "rc": "cli.js"
-      }
-    },
-    "node_modules/readable-stream": {
-      "version": "3.6.2",
-      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.6.2.tgz",
-      "integrity": "sha512-9u/sniCrY3D5WdsERHzHE4G2YCXqoG5FTHUiCC4SIbr6XcLZBY05ya9EKjYek9O5xOAwjGq+1JdGBAS7Q9ScoA==",
-      "license": "MIT",
-      "dependencies": {
-        "inherits": "^2.0.3",
-        "string_decoder": "^1.1.1",
-        "util-deprecate": "^1.0.1"
-      },
-      "engines": {
-        "node": ">= 6"
-      }
-    },
     "node_modules/resolve-pkg-maps": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/resolve-pkg-maps/-/resolve-pkg-maps-1.0.0.tgz",
@@ -2693,51 +2406,6 @@
         "url": "https://github.com/sponsors/isaacs"
       }
     },
-    "node_modules/simple-concat": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/simple-concat/-/simple-concat-1.0.1.tgz",
-      "integrity": "sha512-cSFtAPtRhljv69IK0hTVZQ+OfE9nePi/rtJmw5UjHeVyVroEqJXP1sFztKUy1qU+xvz3u/sfYJLa947b7nAN2Q==",
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/feross"
-        },
-        {
-          "type": "patreon",
-          "url": "https://www.patreon.com/feross"
-        },
-        {
-          "type": "consulting",
-          "url": "https://feross.org/support"
-        }
-      ],
-      "license": "MIT"
-    },
-    "node_modules/simple-get": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/simple-get/-/simple-get-4.0.1.tgz",
-      "integrity": "sha512-brv7p5WgH0jmQJr1ZDDfKDOSeWWg+OVypG99A/5vYGPqJ6pxiaHLy8nxtFjBA7oMa01ebA9gfh1uMCFqOuXxvA==",
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/feross"
-        },
-        {
-          "type": "patreon",
-          "url": "https://www.patreon.com/feross"
-        },
-        {
-          "type": "consulting",
-          "url": "https://feross.org/support"
-        }
-      ],
-      "license": "MIT",
-      "dependencies": {
-        "decompress-response": "^6.0.0",
-        "once": "^1.3.1",
-        "simple-concat": "^1.0.0"
-      }
-    },
     "node_modules/split2": {
       "version": "4.2.0",
       "resolved": "https://registry.npmjs.org/split2/-/split2-4.2.0.tgz",
@@ -2756,15 +2424,6 @@
         "node": ">= 0.8"
       }
     },
-    "node_modules/string_decoder": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.3.0.tgz",
-      "integrity": "sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA==",
-      "license": "MIT",
-      "dependencies": {
-        "safe-buffer": "~5.2.0"
-      }
-    },
     "node_modules/string-width": {
       "version": "5.1.2",
       "resolved": "https://registry.npmjs.org/string-width/-/string-width-5.1.2.tgz",
@@ -2861,43 +2520,6 @@
         "node": ">=8"
       }
     },
-    "node_modules/strip-json-comments": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/strip-json-comments/-/strip-json-comments-2.0.1.tgz",
-      "integrity": "sha512-4gB8na07fecVVkOI6Rs4e7T6NOTki5EmL7TUduTs6bu3EdnSycntVJ4re8kgZA+wx9IueI2Y11bfbgwtzuE0KQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
-    "node_modules/tar-fs": {
-      "version": "2.1.4",
-      "resolved": "https://registry.npmjs.org/tar-fs/-/tar-fs-2.1.4.tgz",
-      "integrity": "sha512-mDAjwmZdh7LTT6pNleZ05Yt65HC3E+NiQzl672vQG38jIrehtJk/J3mNwIg+vShQPcLF/LV7CMnDW6vjj6sfYQ==",
-      "license": "MIT",
-      "dependencies": {
-        "chownr": "^1.1.1",
-        "mkdirp-classic": "^0.5.2",
-        "pump": "^3.0.0",
-        "tar-stream": "^2.1.4"
-      }
-    },
-    "node_modules/tar-stream": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/tar-stream/-/tar-stream-2.2.0.tgz",
-      "integrity": "sha512-ujeqbceABgwMZxEJnk2HDY2DlnUZ+9oEcb1KzTVfYHio0UE6dG71n60d8D2I4qNvleWrrXpmjpt7vZeF1LnMZQ==",
-      "license": "MIT",
-      "dependencies": {
-        "bl": "^4.0.3",
-        "end-of-stream": "^1.4.1",
-        "fs-constants": "^1.0.0",
-        "inherits": "^2.0.3",
-        "readable-stream": "^3.1.1"
-      },
-      "engines": {
-        "node": ">=6"
-      }
-    },
     "node_modules/toidentifier": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/toidentifier/-/toidentifier-1.0.1.tgz",
@@ -2927,18 +2549,6 @@
         "fsevents": "~2.3.3"
       }
     },
-    "node_modules/tunnel-agent": {
-      "version": "0.6.0",
-      "resolved": "https://registry.npmjs.org/tunnel-agent/-/tunnel-agent-0.6.0.tgz",
-      "integrity": "sha512-McnNiV1l8RYeY8tBgEpuodCC1mLUdbSN+CYBL7kJsJNInOP8UjDDEwdk6Mw60vdLLrr5NHKZhMAOSrR2NZuQ+w==",
-      "license": "Apache-2.0",
-      "dependencies": {
-        "safe-buffer": "^5.0.1"
-      },
-      "engines": {
-        "node": "*"
-      }
-    },
     "node_modules/type-is": {
       "version": "1.6.18",
       "resolved": "https://registry.npmjs.org/type-is/-/type-is-1.6.18.tgz",
@@ -2982,12 +2592,6 @@
         "node": ">= 0.8"
       }
     },
-    "node_modules/util-deprecate": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz",
-      "integrity": "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==",
-      "license": "MIT"
-    },
     "node_modules/utils-merge": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/utils-merge/-/utils-merge-1.0.1.tgz",
@@ -3121,12 +2725,6 @@
         "node": ">=8"
       }
     },
-    "node_modules/wrappy": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
-      "integrity": "sha512-l4Sp/DRseor9wL6EvV2+TuQn63dMkPjZ/sp9XkghTEbV9KlPS1xUsZ3u7/IQO4wxtcFB4bgpQPRcR3QCvezPcQ==",
-      "license": "ISC"
-    },
     "node_modules/xtend": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.2.tgz",
diff --git a/backend/package.json b/backend/package.json
index 36aaee1..1e578cb 100755
--- a/backend/package.json
+++ b/backend/package.json
@@ -10,7 +10,6 @@
   },
   "dependencies": {
     "bcrypt": "^6.0.0",
-    "better-sqlite3": "^11.9.1",
     "cookie-parser": "^1.4.7",
     "cors": "^2.8.5",
     "dotenv": "^17.3.1",
@@ -23,7 +22,6 @@
   },
   "devDependencies": {
     "@types/bcrypt": "^6.0.0",
-    "@types/better-sqlite3": "^7.6.12",
     "@types/cookie-parser": "^1.4.10",
     "@types/cors": "^2.8.17",
     "@types/express": "^5.0.0",
diff --git a/backend/src/db/database.ts b/backend/src/db/database.ts
deleted file mode 100755
index de1109c..0000000
--- a/backend/src/db/database.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-import Database from 'better-sqlite3'
-import { fileURLToPath } from 'url'
-import { dirname, join } from 'path'
-
-const __filename = fileURLToPath(import.meta.url)
-const __dirname = dirname(__filename)
-
-const dbPath = join(__dirname, '../../data/layers.db')
-
-export const db = new Database(dbPath)
-
-// 데이터베이스 초기화
-export function initDatabase() {
-  db.exec(`
-    CREATE TABLE IF NOT EXISTS layers (
-      cmn_cd TEXT PRIMARY KEY,
-      up_cmn_cd TEXT,
-      cmn_cd_full_nm TEXT NOT NULL,
-      cmn_cd_nm TEXT NOT NULL,
-      cmn_cd_level INTEGER NOT NULL,
-      clnm TEXT,
-      FOREIGN KEY (up_cmn_cd) REFERENCES layers(cmn_cd)
-    );
-
-    CREATE INDEX IF NOT EXISTS idx_up_cmn_cd ON layers(up_cmn_cd);
-    CREATE INDEX IF NOT EXISTS idx_cmn_cd_level ON layers(cmn_cd_level);
-  `)
-}
-
-export default db
diff --git a/backend/src/db/seed.ts b/backend/src/db/seed.ts
index 1a27bf1..1beff4f 100755
--- a/backend/src/db/seed.ts
+++ b/backend/src/db/seed.ts
@@ -1,91 +1,106 @@
+import 'dotenv/config'
 import fs from 'fs'
 import path from 'path'
 import { fileURLToPath } from 'url'
 import { dirname } from 'path'
-import db, { initDatabase } from './database.js'
+import { wingPool } from './wingDb.js'
 
 const __filename = fileURLToPath(import.meta.url)
 const __dirname = dirname(__filename)
 
 async function seedDatabase() {
-  console.log('데이터베이스 초기화 중...')
-  initDatabase()
+  console.log('wing DB 레이어 시드 시작...')
 
-  // 기존 데이터 삭제
-  db.exec('DELETE FROM layers')
+  const client = await wingPool.connect()
 
-  // CSV 파일 읽기
-  const csvPath = path.join(__dirname, '../../../LayerList.csv')
-  const csvContent = fs.readFileSync(csvPath, 'utf-8')
-  
-  // CSV 파싱
-  const lines = csvContent.split('\n')
-  const headers = lines[0].split(',').map(h => h.replace(/"/g, '').trim())
-  
-  const insert = db.prepare(`
-    INSERT INTO layers (cmn_cd, up_cmn_cd, cmn_cd_full_nm, cmn_cd_nm, cmn_cd_level, clnm)
-    VALUES (?, ?, ?, ?, ?, ?)
-  `)
+  try {
+    // CSV 파일 읽기
+    const csvPath = path.join(__dirname, '../../../_reference/LayerList.csv')
+    const csvContent = fs.readFileSync(csvPath, 'utf-8')
 
-  const insertMany = db.transaction((rows: any[]) => {
-    for (const row of rows) {
-      insert.run(row)
-    }
-  })
+    // CSV 파싱
+    const lines = csvContent.split('\n')
 
-  const rows = []
-  
-  for (let i = 1; i < lines.length; i++) {
-    const line = lines[i].trim()
-    if (!line) continue
+    const rows: (string | number | null)[][] = []
 
-    // CSV 파싱 (쉼표로 구분, 따옴표 처리)
-    const values = []
-    let current = ''
-    let inQuotes = false
+    for (let i = 1; i < lines.length; i++) {
+      const line = lines[i].trim()
+      if (!line) continue
 
-    for (let j = 0; j < line.length; j++) {
-      const char = line[j]
-      
-      if (char === '"') {
-        inQuotes = !inQuotes
-      } else if (char === ',' && !inQuotes) {
-        values.push(current.trim())
-        current = ''
-      } else {
-        current += char
+      const values: string[] = []
+      let current = ''
+      let inQuotes = false
+
+      for (let j = 0; j < line.length; j++) {
+        const char = line[j]
+        if (char === '"') {
+          inQuotes = !inQuotes
+        } else if (char === ',' && !inQuotes) {
+          values.push(current.trim())
+          current = ''
+        } else {
+          current += char
+        }
+      }
+      values.push(current.trim())
+
+      const row = values.map(v => {
+        if (v === 'NULL' || v === '') return null
+        return v.replace(/"/g, '')
+      })
+
+      if (row.length >= 6) {
+        rows.push([
+          row[0],                        // LAYER_CD
+          row[1],                        // UP_LAYER_CD
+          row[2],                        // LAYER_FULL_NM
+          row[3],                        // LAYER_NM
+          parseInt(row[4] || '0', 10),   // LAYER_LEVEL
+          row[5],                        // WMS_LAYER_NM
+        ])
       }
     }
-    values.push(current.trim())
 
-    // NULL 값 처리
-    const row = values.map(v => {
-      if (v === 'NULL' || v === '') return null
-      return v.replace(/"/g, '')
-    })
+    console.log(`${rows.length}개의 레이어 데이터 삽입 중...`)
 
-    if (row.length >= 6) {
-      rows.push([
-        row[0], // cmn_cd
-        row[1], // up_cmn_cd
-        row[2], // cmn_cd_full_nm
-        row[3], // cmn_cd_nm
-        parseInt(row[4] || '0'), // cmn_cd_level
-        row[5], // clnm
-      ])
+    await client.query('BEGIN')
+
+    // 기존 데이터 삭제
+    await client.query('DELETE FROM LAYER')
+
+    // FK 제약 때문에 상위 레이어(낮은 레벨)부터 삽입
+    const sortedRows = rows.sort((a, b) => (a[4] as number) - (b[4] as number))
+
+    for (const row of sortedRows) {
+      await client.query(
+        `INSERT INTO LAYER (LAYER_CD, UP_LAYER_CD, LAYER_FULL_NM, LAYER_NM, LAYER_LEVEL, WMS_LAYER_NM)
+         VALUES ($1, $2, $3, $4, $5, $6)
+         ON CONFLICT (LAYER_CD) DO UPDATE SET
+           UP_LAYER_CD = EXCLUDED.UP_LAYER_CD,
+           LAYER_FULL_NM = EXCLUDED.LAYER_FULL_NM,
+           LAYER_NM = EXCLUDED.LAYER_NM,
+           LAYER_LEVEL = EXCLUDED.LAYER_LEVEL,
+           WMS_LAYER_NM = EXCLUDED.WMS_LAYER_NM`,
+        row
+      )
     }
+
+    await client.query('COMMIT')
+
+    // 결과 확인
+    const { rows: countResult } = await client.query('SELECT COUNT(*) as count FROM LAYER')
+    console.log(`시드 완료! 총 ${countResult[0].count}개의 레이어가 저장되었습니다.`)
+  } catch (err) {
+    await client.query('ROLLBACK')
+    console.error('시드 실패:', err)
+    throw err
+  } finally {
+    client.release()
+    await wingPool.end()
   }
-
-  console.log(`${rows.length}개의 레이어 데이터 삽입 중...`)
-  insertMany(rows)
-
-  console.log('시드 완료!')
-  
-  // 결과 확인
-  const count = db.prepare('SELECT COUNT(*) as count FROM layers').get() as { count: number }
-  console.log(`총 ${count.count}개의 레이어가 저장되었습니다.`)
-  
-  db.close()
 }
 
-seedDatabase().catch(console.error)
+seedDatabase().catch((err) => {
+  console.error(err)
+  process.exit(1)
+})
diff --git a/backend/src/db/wingDb.ts b/backend/src/db/wingDb.ts
new file mode 100644
index 0000000..83648a7
--- /dev/null
+++ b/backend/src/db/wingDb.ts
@@ -0,0 +1,33 @@
+import pg from 'pg'
+
+const { Pool } = pg
+
+const wingPool = new Pool({
+  host: process.env.WING_DB_HOST || 'localhost',
+  port: Number(process.env.WING_DB_PORT) || 5432,
+  database: process.env.WING_DB_NAME || 'wing',
+  user: process.env.WING_DB_USER || 'wing',
+  password: process.env.WING_DB_PASSWORD || 'Wing2026',
+  max: 10,
+  idleTimeoutMillis: 30000,
+  connectionTimeoutMillis: 5000,
+})
+
+wingPool.on('error', (err) => {
+  console.error('[wingDb] 예기치 않은 연결 오류:', err.message)
+})
+
+export async function testWingDbConnection(): Promise<boolean> {
+  try {
+    const client = await wingPool.connect()
+    await client.query('SELECT 1')
+    client.release()
+    console.log('[wingDb] wing 데이터베이스 연결 성공')
+    return true
+  } catch (err) {
+    console.warn('[wingDb] wing 데이터베이스 연결 실패:', (err as Error).message)
+    return false
+  }
+}
+
+export { wingPool }
diff --git a/backend/src/routes/layers.ts b/backend/src/routes/layers.ts
index ee50daf..d5ad1cb 100755
--- a/backend/src/routes/layers.ts
+++ b/backend/src/routes/layers.ts
@@ -1,5 +1,5 @@
 import express from 'express'
-import db from '../db/database.js'
+import { wingPool } from '../db/wingDb.js'
 import { enrichLayerWithMetadata } from '../utils/layerIcons.js'
 import {
   sanitizeParams,
@@ -19,14 +19,26 @@ interface Layer {
   clnm: string | null
 }
 
+// DB 컬럼 → API 응답 컬럼 매핑 (프론트엔드 호환성 유지)
+const LAYER_COLUMNS = `
+  LAYER_CD      AS cmn_cd,
+  UP_LAYER_CD   AS up_cmn_cd,
+  LAYER_FULL_NM AS cmn_cd_full_nm,
+  LAYER_NM      AS cmn_cd_nm,
+  LAYER_LEVEL   AS cmn_cd_level,
+  WMS_LAYER_NM  AS clnm
+`.trim()
+
 // 모든 라우트에 파라미터 살균 적용
 router.use(sanitizeParams)
 
 // 모든 레이어 조회
-router.get('/', (_req, res) => {
+router.get('/', async (_req, res) => {
   try {
-    const layers = db.prepare('SELECT * FROM layers ORDER BY cmn_cd').all() as Layer[]
-    const enrichedLayers = layers.map(enrichLayerWithMetadata)
+    const { rows } = await wingPool.query<Layer>(
+      `SELECT ${LAYER_COLUMNS} FROM LAYER WHERE USE_YN = 'Y' ORDER BY LAYER_CD`
+    )
+    const enrichedLayers = rows.map(enrichLayerWithMetadata)
     res.json(enrichedLayers)
   } catch {
     res.status(500).json({ error: '레이어 조회 실패' })
@@ -34,17 +46,19 @@ router.get('/', (_req, res) => {
 })
 
 // 계층 구조로 변환된 레이어 트리 조회
-router.get('/tree/all', (_req, res) => {
+router.get('/tree/all', async (_req, res) => {
   try {
-    const layers = db.prepare('SELECT * FROM layers ORDER BY cmn_cd').all() as Layer[]
-    const enrichedLayers = layers.map(enrichLayerWithMetadata)
+    const { rows } = await wingPool.query<Layer>(
+      `SELECT ${LAYER_COLUMNS} FROM LAYER WHERE USE_YN = 'Y' ORDER BY LAYER_CD`
+    )
+    const enrichedLayers = rows.map(enrichLayerWithMetadata)
 
-    const layerMap = new Map<string, any>()
+    const layerMap = new Map<string, Layer & { children: Layer[] }>()
     enrichedLayers.forEach(layer => {
       layerMap.set(layer.cmn_cd, { ...layer, children: [] })
     })
 
-    const rootLayers: any[] = []
+    const rootLayers: (Layer & { children: Layer[] })[] = []
     enrichedLayers.forEach(layer => {
       const layerNode = layerMap.get(layer.cmn_cd)!
       if (layer.up_cmn_cd === null) {
@@ -64,10 +78,12 @@ router.get('/tree/all', (_req, res) => {
 })
 
 // WMS 레이어만 조회
-router.get('/wms/all', (_req, res) => {
+router.get('/wms/all', async (_req, res) => {
   try {
-    const layers = db.prepare('SELECT * FROM layers WHERE clnm IS NOT NULL ORDER BY cmn_cd').all() as Layer[]
-    const enrichedLayers = layers.map(enrichLayerWithMetadata)
+    const { rows } = await wingPool.query<Layer>(
+      `SELECT ${LAYER_COLUMNS} FROM LAYER WHERE WMS_LAYER_NM IS NOT NULL AND USE_YN = 'Y' ORDER BY LAYER_CD`
+    )
+    const enrichedLayers = rows.map(enrichLayerWithMetadata)
     res.json(enrichedLayers)
   } catch {
     res.status(500).json({ error: 'WMS 레이어 조회 실패' })
@@ -75,11 +91,10 @@ router.get('/wms/all', (_req, res) => {
 })
 
 // 특정 레벨의 레이어만 조회
-router.get('/level/:level', (req, res) => {
+router.get('/level/:level', async (req, res) => {
   try {
     const level = parseInt(req.params.level, 10)
 
-    // 입력 검증: 레벨은 1~10 범위의 정수
     if (!isValidNumber(level, 1, 10)) {
       return res.status(400).json({
         error: '유효하지 않은 레벨값',
@@ -87,9 +102,11 @@ router.get('/level/:level', (req, res) => {
       })
     }
 
-    // 파라미터화된 쿼리 사용 (SQL 인젝션 방지)
-    const layers = db.prepare('SELECT * FROM layers WHERE cmn_cd_level = ? ORDER BY cmn_cd').all(level) as Layer[]
-    const enrichedLayers = layers.map(enrichLayerWithMetadata)
+    const { rows } = await wingPool.query<Layer>(
+      `SELECT ${LAYER_COLUMNS} FROM LAYER WHERE LAYER_LEVEL = $1 AND USE_YN = 'Y' ORDER BY LAYER_CD`,
+      [level]
+    )
+    const enrichedLayers = rows.map(enrichLayerWithMetadata)
     res.json(enrichedLayers)
   } catch {
     res.status(500).json({ error: '레벨별 레이어 조회 실패' })
@@ -97,11 +114,10 @@ router.get('/level/:level', (req, res) => {
 })
 
 // 특정 부모의 자식 레이어 조회
-router.get('/children/:parentId', (req, res) => {
+router.get('/children/:parentId', async (req, res) => {
   try {
     const parentId = req.params.parentId
 
-    // 입력 검증: 코드 형식 확인 (영숫자, 언더스코어, 하이픈만 허용)
     if (!parentId || !isValidStringLength(parentId, 50) || !/^[a-zA-Z0-9_-]+$/.test(parentId)) {
       return res.status(400).json({
         error: '유효하지 않은 부모 ID',
@@ -110,8 +126,11 @@ router.get('/children/:parentId', (req, res) => {
     }
 
     const sanitizedId = sanitizeString(parentId)
-    const layers = db.prepare('SELECT * FROM layers WHERE up_cmn_cd = ? ORDER BY cmn_cd').all(sanitizedId) as Layer[]
-    const enrichedLayers = layers.map(enrichLayerWithMetadata)
+    const { rows } = await wingPool.query<Layer>(
+      `SELECT ${LAYER_COLUMNS} FROM LAYER WHERE UP_LAYER_CD = $1 AND USE_YN = 'Y' ORDER BY LAYER_CD`,
+      [sanitizedId]
+    )
+    const enrichedLayers = rows.map(enrichLayerWithMetadata)
     res.json(enrichedLayers)
   } catch {
     res.status(500).json({ error: '자식 레이어 조회 실패' })
@@ -119,11 +138,10 @@ router.get('/children/:parentId', (req, res) => {
 })
 
 // 특정 레이어 조회
-router.get('/:id', (req, res) => {
+router.get('/:id', async (req, res) => {
   try {
     const id = req.params.id
 
-    // 입력 검증: ID 형식 확인
     if (!id || !isValidStringLength(id, 50) || !/^[a-zA-Z0-9_-]+$/.test(id)) {
       return res.status(400).json({
         error: '유효하지 않은 레이어 ID',
@@ -132,11 +150,14 @@ router.get('/:id', (req, res) => {
     }
 
     const sanitizedId = sanitizeString(id)
-    const layer = db.prepare('SELECT * FROM layers WHERE cmn_cd = ?').get(sanitizedId) as Layer | undefined
-    if (!layer) {
+    const { rows } = await wingPool.query<Layer>(
+      `SELECT ${LAYER_COLUMNS} FROM LAYER WHERE LAYER_CD = $1`,
+      [sanitizedId]
+    )
+    if (rows.length === 0) {
       return res.status(404).json({ error: '레이어를 찾을 수 없습니다' })
     }
-    const enrichedLayer = enrichLayerWithMetadata(layer)
+    const enrichedLayer = enrichLayerWithMetadata(rows[0])
     res.json(enrichedLayer)
   } catch {
     res.status(500).json({ error: '레이어 조회 실패' })
diff --git a/backend/src/server.ts b/backend/src/server.ts
index 8d312c9..d46dbdc 100755
--- a/backend/src/server.ts
+++ b/backend/src/server.ts
@@ -4,8 +4,8 @@ import cors from 'cors'
 import helmet from 'helmet'
 import rateLimit from 'express-rate-limit'
 import cookieParser from 'cookie-parser'
-import { initDatabase } from './db/database.js'
 import { testAuthDbConnection } from './db/authDb.js'
+import { testWingDbConnection } from './db/wingDb.js'
 import layersRouter from './routes/layers.js'
 import simulationRouter from './routes/simulation.js'
 import authRouter from './auth/authRouter.js'
@@ -113,11 +113,6 @@ app.use(express.urlencoded({ extended: false, limit: BODY_SIZE_LIMIT }))
 app.use(sanitizeBody)
 app.use(sanitizeQuery)
 
-// ============================================================
-// 데이터베이스 초기화
-// ============================================================
-initDatabase()
-
 // ============================================================
 // 라우트
 // ============================================================
@@ -176,6 +171,11 @@ app.use((err: Error, _req: express.Request, res: express.Response, _next: expres
 // ============================================================
 app.listen(PORT, async () => {
   console.log(`서버가 포트 ${PORT}에서 실행 중입니다.`)
+
+  // wing DB (운영 데이터) 연결 확인
+  await testWingDbConnection()
+
+  // wing_auth DB (인증 데이터) 연결 확인
   const connected = await testAuthDbConnection()
   if (connected) {
     // SETTING_VAL VARCHAR(500) → TEXT 마이그레이션 (메뉴 설정 JSON 확장 대응)
diff --git a/database/migration/001_layer_table.sql b/database/migration/001_layer_table.sql
new file mode 100644
index 0000000..1d43b13
--- /dev/null
+++ b/database/migration/001_layer_table.sql
@@ -0,0 +1,36 @@
+-- ================================================================
+-- 001: LAYER 테이블 생성 (SQLite layers.db → PostgreSQL wing DB 마이그레이션)
+-- ================================================================
+-- 기존 SQLite layers 테이블의 데이터를 PostgreSQL wing DB로 이전
+-- 공공데이터베이스 표준화 관리 매뉴얼(2021.06) 네이밍 적용
+-- ================================================================
+
+CREATE TABLE IF NOT EXISTS LAYER (
+  LAYER_CD      VARCHAR(50)   NOT NULL,  -- 레이어코드 (기존 cmn_cd)
+  UP_LAYER_CD   VARCHAR(50),             -- 상위레이어코드 (기존 up_cmn_cd)
+  LAYER_FULL_NM VARCHAR(200)  NOT NULL,  -- 레이어전체명 (기존 cmn_cd_full_nm)
+  LAYER_NM      VARCHAR(100)  NOT NULL,  -- 레이어명 (기존 cmn_cd_nm)
+  LAYER_LEVEL   INTEGER       NOT NULL,  -- 레이어레벨 (기존 cmn_cd_level)
+  WMS_LAYER_NM  VARCHAR(100),            -- WMS레이어명 (기존 clnm)
+  USE_YN        CHAR(1)       NOT NULL DEFAULT 'Y',  -- 사용여부
+  SORT_ORD      INTEGER       DEFAULT 0,             -- 정렬순서
+  REG_DTM       TIMESTAMPTZ   NOT NULL DEFAULT NOW(), -- 등록일시
+  CONSTRAINT PK_LAYER PRIMARY KEY (LAYER_CD),
+  CONSTRAINT FK_LAYER_UP FOREIGN KEY (UP_LAYER_CD) REFERENCES LAYER(LAYER_CD),
+  CONSTRAINT CK_LAYER_USE_YN CHECK (USE_YN IN ('Y', 'N'))
+);
+
+COMMENT ON TABLE  LAYER IS '레이어';
+COMMENT ON COLUMN LAYER.LAYER_CD      IS '레이어코드 (예: LYR001001)';
+COMMENT ON COLUMN LAYER.UP_LAYER_CD   IS '상위레이어코드 (상위 레이어 참조)';
+COMMENT ON COLUMN LAYER.LAYER_FULL_NM IS '레이어전체명 (계층 경로 포함 전체 명칭)';
+COMMENT ON COLUMN LAYER.LAYER_NM      IS '레이어명 (표시용 짧은 명칭)';
+COMMENT ON COLUMN LAYER.LAYER_LEVEL   IS '레이어레벨 (1:최상위, 2:중분류, 3:소분류 ...)';
+COMMENT ON COLUMN LAYER.WMS_LAYER_NM  IS 'WMS레이어명 (GeoServer WMS 레이어 식별자)';
+COMMENT ON COLUMN LAYER.USE_YN        IS '사용여부 (Y:사용, N:미사용)';
+COMMENT ON COLUMN LAYER.SORT_ORD      IS '정렬순서';
+COMMENT ON COLUMN LAYER.REG_DTM       IS '등록일시';
+
+CREATE INDEX IF NOT EXISTS IDX_LAYER_UP    ON LAYER(UP_LAYER_CD);
+CREATE INDEX IF NOT EXISTS IDX_LAYER_LEVEL ON LAYER(LAYER_LEVEL);
+CREATE INDEX IF NOT EXISTS IDX_LAYER_USE   ON LAYER(USE_YN);
diff --git a/docs/COMMON-GUIDE.md b/docs/COMMON-GUIDE.md
index e4f2b25..b77b5a9 100644
--- a/docs/COMMON-GUIDE.md
+++ b/docs/COMMON-GUIDE.md
@@ -291,14 +291,13 @@ const mutation = useMutation({
 
 ### DB 접근
 ```typescript
-// PostgreSQL (인증 DB)
-import { authPool } from '../db/authDb.js'
-const result = await authPool.query('SELECT * FROM TABLE WHERE id = $1', [id])
+// PostgreSQL — wing DB (운영 데이터: 레이어, 사고, 예측 등)
+import { wingPool } from '../db/wingDb.js'
+const result = await wingPool.query('SELECT * FROM LAYER WHERE LAYER_CD = $1', [id])
 
-// SQLite (레이어 DB)
-import { getDb } from '../db/database.js'
-const db = getDb()
-const rows = db.prepare('SELECT * FROM table').all()
+// PostgreSQL — wing_auth DB (인증 데이터: 사용자, 역할, 권한 등)
+import { authPool } from '../db/authDb.js'
+const result = await authPool.query('SELECT * FROM AUTH_USER WHERE USER_ID = $1', [id])
 ```
 
 ---
diff --git a/docs/README.md b/docs/README.md
index f077b30..1606965 100755
--- a/docs/README.md
+++ b/docs/README.md
@@ -34,12 +34,12 @@ claude
 | 영역 | 기술 |
 |------|------|
 | Frontend | React 19, Vite 7, TypeScript 5.9, Tailwind CSS 3 |
-| Backend | Express 4, TypeScript, better-sqlite3 (레이어), pg (인증) |
+| Backend | Express 4, TypeScript, PostgreSQL (pg) |
 | 상태 관리 | Zustand (클라이언트), TanStack Query (서버) |
 | 지도 | Leaflet, OpenLayers |
 | 실시간 | Socket.IO |
 | 인증 | JWT (HttpOnly Cookie), Google OAuth |
-| DB | PostgreSQL 16 + PostGIS (운영 DB 직접 연결), SQLite |
+| DB | PostgreSQL 16 + PostGIS (wing + wing_auth) |
 | CI/CD | Gitea Actions |
 
 ---
@@ -73,7 +73,7 @@ wing/
 │       ├── audit/             감사 로그
 │       ├── routes/            레이어, 시뮬레이션
 │       ├── middleware/        보안 (입력 살균, rate-limit)
-│       └── db/                DB 연결 (PostgreSQL, SQLite)
+│       └── db/                DB 연결 (PostgreSQL: wing, wing_auth)
 ├── database/                  SQL 초기화 스크립트
 ├── docs/                      개발 문서
 ├── .claude/                   팀 워크플로우 (rules, skills, scripts)