diff --git a/apps/api/src/services/channel-notification.service.ts b/apps/api/src/services/channel-notification.service.ts
index 641f8e5..58ec938 100644
--- a/apps/api/src/services/channel-notification.service.ts
+++ b/apps/api/src/services/channel-notification.service.ts
@@ -17,6 +17,7 @@ import { getAppTimezone, getNotificationChannelSettings, getSetting, setSetting
 import { validateNotificationTargetUrl } from './notification-url.service'
 import { toIsoDate } from '../utils/date'
 import { formatDateInTimezone } from '../utils/timezone'
+import { prisma } from '../db'
 
 type NotificationDispatchParams = {
   eventType: WebhookEventType
@@ -70,11 +71,33 @@ export type NotificationChannelResult = {
   message?: string
 }
 
+const NOTIFICATION_DEDUP_KEY_PREFIX = 'notification:'
+export const NOTIFICATION_DEDUP_RETENTION_DAYS = 30
+
 function buildNotificationKey(
   channel: 'email' | 'pushplus' | 'telegram' | 'serverchan' | 'gotify',
   params: NotificationDispatchParams
 ) {
-  return `notification:${channel}:${params.eventType}:${params.resourceKey}:${params.periodKey}`
+  return `${NOTIFICATION_DEDUP_KEY_PREFIX}${channel}:${params.eventType}:${params.resourceKey}:${params.periodKey}`
+}
+
+export async function cleanupOldNotificationDedupSettings(
+  now = new Date(),
+  retentionDays = NOTIFICATION_DEDUP_RETENTION_DAYS
+) {
+  const cutoff = new Date(now.getTime() - retentionDays * 24 * 60 * 60 * 1000)
+  const result = await prisma.setting.deleteMany({
+    where: {
+      key: {
+        startsWith: NOTIFICATION_DEDUP_KEY_PREFIX
+      },
+      updatedAt: {
+        lt: cutoff
+      }
+    }
+  })
+
+  return result.count
 }
 
 const CHANNEL_LABELS: Record<NotificationChannelResult['channel'], string> = {
diff --git a/apps/api/src/services/scheduler.service.ts b/apps/api/src/services/scheduler.service.ts
index c43b7f1..7f302cf 100644
--- a/apps/api/src/services/scheduler.service.ts
+++ b/apps/api/src/services/scheduler.service.ts
@@ -5,6 +5,7 @@ import { scanRenewalNotifications } from './notification.service'
 import { parseDailyCronForTimezoneGate, runDailyTaskAtLocalHour } from './cron-gate.service'
 import { getAppTimezone } from './settings.service'
 import { autoRenewDueSubscriptions, reconcileExpiredSubscriptions } from './subscription.service'
+import { cleanupOldNotificationDedupSettings } from './channel-notification.service'
 
 type NotificationScan = Awaited<ReturnType<typeof scanRenewalNotifications>>
 
@@ -50,6 +51,15 @@ function logReminderScan(result: NotificationScan) {
   )
 }
 
+export async function cleanupNotificationDedupSettingsOncePerDay(now = new Date()) {
+  return runDailyTaskAtLocalHour('cleanupNotificationDedupSettings', await getAppTimezone(), 3, now, async () => {
+    const deleted = await cleanupOldNotificationDedupSettings(now)
+    if (deleted > 0) {
+      console.log(`[cron] notification dedup cleanup：清理 ${deleted} 条旧记录`)
+    }
+  })
+}
+
 export function startSchedulers() {
   const refreshRatesCronGate = parseDailyCronForTimezoneGate(config.cronRefreshRates)
   cron.schedule(refreshRatesCronGate?.triggerCron ?? config.cronRefreshRates, async () => {
@@ -81,6 +91,7 @@ export function startSchedulers() {
     try {
       await autoRenewDueSubscriptions()
       await reconcileExpiredSubscriptions()
+      await cleanupNotificationDedupSettingsOncePerDay()
       const result = await scanRenewalNotifications()
       logReminderScan(result)
     } catch (e) {
diff --git a/apps/api/tests/unit/notification-dedup-cleanup.test.ts b/apps/api/tests/unit/notification-dedup-cleanup.test.ts
new file mode 100644
index 0000000..71eb8f9
--- /dev/null
+++ b/apps/api/tests/unit/notification-dedup-cleanup.test.ts
@@ -0,0 +1,98 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const cleanupState = vi.hoisted(() => ({
+  settingDeleteManyMock: vi.fn(),
+  getAppTimezoneMock: vi.fn(),
+  runDailyTaskAtLocalHourMock: vi.fn()
+}))
+
+vi.mock('../../src/db', () => ({
+  prisma: {
+    setting: {
+      deleteMany: cleanupState.settingDeleteManyMock
+    }
+  }
+}))
+
+vi.mock('../../src/services/settings.service', () => ({
+  getAppTimezone: cleanupState.getAppTimezoneMock
+}))
+
+vi.mock('../../src/services/cron-gate.service', () => ({
+  parseDailyCronForTimezoneGate: vi.fn(),
+  runDailyTaskAtLocalHour: cleanupState.runDailyTaskAtLocalHourMock
+}))
+
+vi.mock('node-cron', () => ({
+  default: {
+    schedule: vi.fn()
+  }
+}))
+
+import {
+  cleanupOldNotificationDedupSettings,
+  NOTIFICATION_DEDUP_RETENTION_DAYS
+} from '../../src/services/channel-notification.service'
+import { cleanupNotificationDedupSettingsOncePerDay } from '../../src/services/scheduler.service'
+
+describe('notification dedup cleanup', () => {
+  beforeEach(() => {
+    cleanupState.settingDeleteManyMock.mockReset()
+    cleanupState.getAppTimezoneMock.mockReset()
+    cleanupState.runDailyTaskAtLocalHourMock.mockReset()
+    cleanupState.settingDeleteManyMock.mockResolvedValue({ count: 2 })
+    cleanupState.getAppTimezoneMock.mockResolvedValue('Asia/Shanghai')
+    cleanupState.runDailyTaskAtLocalHourMock.mockImplementation(async (_key, _timezone, _hour, _now, task) => {
+      await task()
+      return true
+    })
+  })
+
+  it('uses a 30-day default retention window for notification dedup settings', async () => {
+    const now = new Date('2026-05-01T12:00:00.000Z')
+    const deleted = await cleanupOldNotificationDedupSettings(now)
+
+    expect(NOTIFICATION_DEDUP_RETENTION_DAYS).toBe(30)
+    expect(deleted).toBe(2)
+    expect(cleanupState.settingDeleteManyMock).toHaveBeenCalledWith({
+      where: {
+        key: {
+          startsWith: 'notification:'
+        },
+        updatedAt: {
+          lt: new Date('2026-04-01T12:00:00.000Z')
+        }
+      }
+    })
+  })
+
+  it('allows callers to override the retention window', async () => {
+    const now = new Date('2026-05-01T12:00:00.000Z')
+    await cleanupOldNotificationDedupSettings(now, 90)
+
+    expect(cleanupState.settingDeleteManyMock).toHaveBeenCalledWith({
+      where: {
+        key: {
+          startsWith: 'notification:'
+        },
+        updatedAt: {
+          lt: new Date('2026-01-31T12:00:00.000Z')
+        }
+      }
+    })
+  })
+
+  it('runs the cleanup through a daily local-time gate', async () => {
+    const now = new Date('2026-05-01T12:00:00.000Z')
+    await cleanupNotificationDedupSettingsOncePerDay(now)
+
+    expect(cleanupState.runDailyTaskAtLocalHourMock).toHaveBeenCalledWith(
+      'cleanupNotificationDedupSettings',
+      'Asia/Shanghai',
+      3,
+      now,
+      expect.any(Function)
+    )
+    expect(cleanupState.settingDeleteManyMock).toHaveBeenCalledTimes(1)
+  })
+})