diff --git a/apps/cli/src/sync/routes.test.ts b/apps/cli/src/sync/routes.test.ts
new file mode 100644
index 00000000..835e41ce
--- /dev/null
+++ b/apps/cli/src/sync/routes.test.ts
@@ -0,0 +1,54 @@
+import assert from 'node:assert/strict'
+import fs from 'node:fs'
+import os from 'node:os'
+import path from 'node:path'
+import test from 'node:test'
+import Fastify from 'fastify'
+import { DataSourceManager } from '@openchatlab/sync'
+import { registerAutomationRoutes } from './routes'
+
+function makeTempDir(): string {
+  const baseDir = fs.existsSync('/private/tmp') ? '/private/tmp' : os.tmpdir()
+  return fs.mkdtempSync(path.join(baseDir, 'chatlab-sync-routes-'))
+}
+
+test('DELETE import session deletes imported local session when deleteData=true', async () => {
+  const settingsDir = makeTempDir()
+  const dsManager = new DataSourceManager(settingsDir)
+  const ds = dsManager.add({
+    baseUrl: 'http://example.com',
+    token: 'token',
+    intervalMinutes: 60,
+  })
+  const [session] = dsManager.addSessions(ds.id, [{ name: 'First chat', remoteSessionId: 'remote-1' }])
+  dsManager.updateSession(ds.id, session.id, { targetSessionId: 'local-1' })
+
+  const deletedSessionIds: string[] = []
+  const app = Fastify()
+  registerAutomationRoutes(app, {
+    dsManager,
+    pullEngine: {
+      triggerPull: async () => ({ success: true, newMessageCount: 0 }),
+      triggerPullAll: async () => ({ success: true, newMessageCount: 0 }),
+      getProgress: () => [],
+    } as any,
+    dbManager: {
+      deleteSessionDatabaseFiles: (sessionId: string) => {
+        deletedSessionIds.push(sessionId)
+      },
+    } as any,
+    serverInfo: { port: 5200, host: '127.0.0.1', token: 'api-token' },
+  })
+  await app.ready()
+
+  const resp = await app.inject({
+    method: 'DELETE',
+    url: `/_web/automation/data-sources/${ds.id}/sessions/${session.id}?deleteData=true`,
+  })
+
+  await app.close()
+
+  assert.equal(resp.statusCode, 200)
+  assert.deepEqual(deletedSessionIds, ['local-1'])
+  assert.equal(dsManager.get(ds.id)?.sessions.length, 0)
+})
diff --git a/apps/cli/src/sync/routes.ts b/apps/cli/src/sync/routes.ts
index a1909050..8d146341 100644
--- a/apps/cli/src/sync/routes.ts
+++ b/apps/cli/src/sync/routes.ts
@@ -91,10 +91,7 @@ export function registerAutomationRoutes(server: FastifyInstance, ctx: SyncRoute
     if (!removed) return reply.code(404).send({ error: 'Session not found' })
     reloadTimer(request.params.id)
     if (request.query.deleteData === 'true' && removed.targetSessionId) {
-      dbManager.close(removed.targetSessionId)
-      const dbPath = dbManager.getDbPath(removed.targetSessionId)
-      const fs = await import('node:fs')
-      if (fs.existsSync(dbPath)) fs.unlinkSync(dbPath)
+      dbManager.deleteSessionDatabaseFiles(removed.targetSessionId)
     }
     return { success: true }
   })
diff --git a/packages/node-runtime/src/database-manager.ts b/packages/node-runtime/src/database-manager.ts
index 7c04022e..07321bb9 100644
--- a/packages/node-runtime/src/database-manager.ts
+++ b/packages/node-runtime/src/database-manager.ts
@@ -18,6 +18,7 @@ import {
   getSchemaVersion,
 } from '@openchatlab/core'
 import { openBetterSqliteDatabase } from './better-sqlite3-adapter'
+import { deleteSessionCache } from './cache/session-cache'
 import { assertDataDirCompatible, type RuntimeIdentity } from './data-dir-compat'
 import {
   CHAT_DB_COMPATIBILITY_RAISES,
@@ -225,10 +226,15 @@ export class DatabaseManager {
     return adapter
   }
 
-  deleteSessionDatabaseFiles(sessionId: string): void {
+  /**
+   * 删除一个会话在本地留下的完整文件集合。
+   * SQLite WAL 模式会产生 sidecar 文件，前端查询还会写 JSON 缓存；只删主库会让列表和后续同步读到脏状态。
+   */
+  deleteSessionDatabaseFiles(sessionId: string): boolean {
     this.close(sessionId)
 
     const dbPath = this.getDbPath(sessionId)
+    const existed = ['', '-wal', '-shm'].some((suffix) => fs.existsSync(dbPath + suffix))
     for (const suffix of ['', '-wal', '-shm']) {
       try {
         const filePath = dbPath + suffix
@@ -237,6 +243,10 @@ export class DatabaseManager {
         /* ignore cleanup failures */
       }
     }
+    const cacheDir = this.pathProvider.getCacheDir()
+    deleteSessionCache(sessionId, cacheDir)
+    deleteSessionCache(sessionId, path.join(cacheDir, 'query'))
+    return existed
   }
 
   raiseCurrentChatDbCompatibilityGate(): void {
diff --git a/packages/node-runtime/src/services/adapters/database-manager-adapter.test.ts b/packages/node-runtime/src/services/adapters/database-manager-adapter.test.ts
new file mode 100644
index 00000000..bfbddb93
--- /dev/null
+++ b/packages/node-runtime/src/services/adapters/database-manager-adapter.test.ts
@@ -0,0 +1,55 @@
+import assert from 'node:assert/strict'
+import fs from 'node:fs'
+import os from 'node:os'
+import path from 'node:path'
+import test from 'node:test'
+import type { PathProvider } from '@openchatlab/core'
+import { DatabaseManager } from '../../database-manager'
+import { createDatabaseManagerAdapter } from './database-manager-adapter'
+
+function makeTempDir(): string {
+  const baseDir = fs.existsSync('/private/tmp') ? '/private/tmp' : os.tmpdir()
+  return fs.mkdtempSync(path.join(baseDir, 'chatlab-db-adapter-'))
+}
+
+function createPathProvider(root: string): PathProvider {
+  return {
+    getSystemDir: () => root,
+    getUserDataDir: () => path.join(root, 'data'),
+    getDatabaseDir: () => path.join(root, 'data', 'databases'),
+    getAiDataDir: () => path.join(root, 'ai'),
+    getSettingsDir: () => path.join(root, 'settings'),
+    getCacheDir: () => path.join(root, 'cache'),
+    getTempDir: () => path.join(root, 'temp'),
+    getLogsDir: () => path.join(root, 'logs'),
+    getDownloadsDir: () => path.join(root, 'downloads'),
+  }
+}
+
+test('DatabaseManager adapter deletes session database sidecar files and caches', () => {
+  const root = makeTempDir()
+  const pathProvider = createPathProvider(root)
+  const manager = new DatabaseManager(pathProvider, { allowMissingRuntimeForTests: true })
+  const adapter = createDatabaseManagerAdapter(manager)
+
+  const sessionId = 'synced-session'
+  const dbPath = manager.getDbPath(sessionId)
+  fs.mkdirSync(path.dirname(dbPath), { recursive: true })
+  for (const suffix of ['', '-wal', '-shm']) {
+    fs.writeFileSync(dbPath + suffix, 'stale-data', 'utf-8')
+  }
+
+  const cachePath = path.join(pathProvider.getCacheDir(), `${sessionId}.cache.json`)
+  const queryCachePath = path.join(pathProvider.getCacheDir(), 'query', `${sessionId}.cache.json`)
+  fs.mkdirSync(path.dirname(cachePath), { recursive: true })
+  fs.mkdirSync(path.dirname(queryCachePath), { recursive: true })
+  fs.writeFileSync(cachePath, '{}', 'utf-8')
+  fs.writeFileSync(queryCachePath, '{}', 'utf-8')
+
+  assert.equal(adapter.deleteSessionFile(sessionId), true)
+  assert.equal(fs.existsSync(dbPath), false)
+  assert.equal(fs.existsSync(dbPath + '-wal'), false)
+  assert.equal(fs.existsSync(dbPath + '-shm'), false)
+  assert.equal(fs.existsSync(cachePath), false)
+  assert.equal(fs.existsSync(queryCachePath), false)
+})
diff --git a/packages/node-runtime/src/services/adapters/database-manager-adapter.ts b/packages/node-runtime/src/services/adapters/database-manager-adapter.ts
index 61422c66..d1316db6 100644
--- a/packages/node-runtime/src/services/adapters/database-manager-adapter.ts
+++ b/packages/node-runtime/src/services/adapters/database-manager-adapter.ts
@@ -5,7 +5,6 @@
  * interface expected by session/member services.
  */
 
-import * as fs from 'fs'
 import type { DatabaseAdapter } from '@openchatlab/core'
 import type { DatabaseManager } from '../../database-manager'
 import type { SessionRuntimeAdapter } from './types'
@@ -19,11 +18,7 @@ export function createDatabaseManagerAdapter(dbManager: DatabaseManager): Sessio
     getDbPath: (sessionId) => dbManager.getDbPath(sessionId),
 
     deleteSessionFile(sessionId: string): boolean {
-      dbManager.close(sessionId)
-      const dbPath = dbManager.getDbPath(sessionId)
-      if (!fs.existsSync(dbPath)) return false
-      fs.unlinkSync(dbPath)
-      return true
+      return dbManager.deleteSessionDatabaseFiles(sessionId)
     },
 
     ensureReadonly(sessionId: string): DatabaseAdapter {
diff --git a/packages/node-runtime/src/services/adapters/types.ts b/packages/node-runtime/src/services/adapters/types.ts
index 48a75fa9..ae3e84be 100644
--- a/packages/node-runtime/src/services/adapters/types.ts
+++ b/packages/node-runtime/src/services/adapters/types.ts
@@ -14,7 +14,7 @@ export interface SessionRuntimeAdapter {
   closeSession(sessionId: string): void
   getDbPath(sessionId: string): string
 
-  /** Delete the session database file. Returns false if not found. */
+  /** Delete the session database files and cache. Returns false if not found. */
   deleteSessionFile(sessionId: string): boolean
 
   /** Open readonly, throw 404 if not found. */
diff --git a/packages/node-runtime/src/services/session-service.ts b/packages/node-runtime/src/services/session-service.ts
index 52bc01d1..2647237e 100644
--- a/packages/node-runtime/src/services/session-service.ts
+++ b/packages/node-runtime/src/services/session-service.ts
@@ -126,7 +126,7 @@ export function updateSessionOwnerId(adapter: SessionRuntimeAdapter, sessionId:
 }
 
 /**
- * Delete a session (close DB + remove file).
+ * Delete a session (close DB + remove files/cache).
  * Returns true if deleted, false if file not found.
  */
 export function deleteSession(adapter: SessionRuntimeAdapter, sessionId: string): boolean {