diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 7c9cb64e..4bcf5b75 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -2456,6 +2456,8 @@ function App() {
       close: () => void;
       isOpen: () => boolean;
   } | null>(null);
+  // 手动「检查更新」发现新版本时，由 useAppUpdateManager 触发打开更新日志弹窗
+  const openReleaseNotesOnManualCheckRef = useRef<(() => void) | null>(null);
   const {
       aboutDisplayVersion,
       aboutInfo,
@@ -2489,6 +2491,7 @@ function App() {
       runtimeBuildType,
       t,
       updateCenterBridgeRef,
+      onManualCheckHasUpdateRef: openReleaseNotesOnManualCheckRef,
   });
   const [aboutLastCheckedAt, setAboutLastCheckedAt] = useState('');
   const [releaseNotesModalOpen, setReleaseNotesModalOpen] = useState(false);
@@ -3637,6 +3640,14 @@ function App() {
           updateCenterBridgeRef.current = null;
       };
   }, [handleOpenSettingsCenterPane]);
+  useEffect(() => {
+      openReleaseNotesOnManualCheckRef.current = () => {
+          setReleaseNotesModalOpen(true);
+      };
+      return () => {
+          openReleaseNotesOnManualCheckRef.current = null;
+      };
+  }, []);
   useEffect(() => {
       if (!isSettingsAboutPaneOpen) {
           return;
@@ -5409,7 +5420,7 @@ function App() {
           key="check"
           icon={<CloudDownloadOutlined />}
           loading={isCheckingForUpdates}
-          onClick={() => checkForUpdates(false)}
+          onClick={() => checkForUpdates(false, true)}
       >
           {t('app.about.action.check_updates')}
       </Button>,
diff --git a/frontend/src/hooks/useAppUpdateManager.test.tsx b/frontend/src/hooks/useAppUpdateManager.test.tsx
index 200d463b..8223f901 100644
--- a/frontend/src/hooks/useAppUpdateManager.test.tsx
+++ b/frontend/src/hooks/useAppUpdateManager.test.tsx
@@ -669,6 +669,46 @@ describe('useAppUpdateManager', () => {
     expect(hook?.lastUpdateInfo?.channel).toBe('dev');
   });
 
+  it('does not invoke the manual-check bridge when a channel change re-check finds an update', async () => {
+    const openReleaseNotes = vi.fn();
+    const openReleaseNotesRef = { current: openReleaseNotes };
+
+    backendApp.SetUpdateChannel.mockResolvedValue({ success: true, data: { channel: 'dev' } });
+    backendApp.CheckForUpdates.mockResolvedValue({
+      success: true,
+      data: {
+        hasUpdate: true,
+        channel: 'dev',
+        currentVersion: '0.8.1',
+        latestVersion: 'dev-a1b2c3d',
+      },
+    });
+
+    const Harness = () => {
+      hook = useAppUpdateManager({
+        runtimeBuildType: 'release',
+        t,
+        onManualCheckHasUpdateRef: openReleaseNotesRef,
+      });
+      return null;
+    };
+
+    act(() => {
+      renderer = create(<Harness />);
+    });
+
+    await act(async () => {
+      await hook?.changeUpdateChannel('dev');
+    });
+
+    expect(backendApp.SetUpdateChannel).toHaveBeenCalledWith('dev');
+    expect(backendApp.CheckForUpdates).toHaveBeenCalledTimes(1);
+    // 通道切换后的自动复查即便发现更新，也不应打开更新日志弹窗（#818 触发边界修正）
+    expect(openReleaseNotes).not.toHaveBeenCalled();
+    expect(hook?.lastUpdateInfo?.hasUpdate).toBe(true);
+    expect(hook?.lastUpdateInfo?.latestVersion).toBe('dev-a1b2c3d');
+  });
+
   it('keeps release metadata from the backend update response', async () => {
     backendApp.CheckForUpdates.mockResolvedValue({
       success: true,
@@ -770,6 +810,114 @@ describe('useAppUpdateManager', () => {
     expect(hook?.lastUpdateInfo?.latestVersion).toBe('0.8.2');
   });
 
+  it('invokes the manual-check bridge when a manual check finds an update', async () => {
+    const openReleaseNotes = vi.fn();
+    const openReleaseNotesRef = { current: openReleaseNotes };
+
+    backendApp.CheckForUpdates.mockResolvedValue({
+      success: true,
+      data: {
+        hasUpdate: true,
+        channel: 'latest',
+        currentVersion: '0.8.1',
+        latestVersion: '0.8.2',
+        releaseNotesUrl: 'https://github.com/Syngnat/GoNavi/releases/tag/v0.8.2',
+      },
+    });
+
+    const Harness = () => {
+      hook = useAppUpdateManager({
+        runtimeBuildType: 'release',
+        t,
+        onManualCheckHasUpdateRef: openReleaseNotesRef,
+      });
+      return null;
+    };
+
+    act(() => {
+      renderer = create(<Harness />);
+    });
+
+    await act(async () => {
+      await hook?.checkForUpdates(false, true);
+    });
+
+    expect(openReleaseNotes).toHaveBeenCalledTimes(1);
+    expect(hook?.lastUpdateInfo?.hasUpdate).toBe(true);
+    expect(hook?.lastUpdateInfo?.latestVersion).toBe('0.8.2');
+  });
+
+  it('does not invoke the manual-check bridge when a manual check finds no update', async () => {
+    const openReleaseNotes = vi.fn();
+    const openReleaseNotesRef = { current: openReleaseNotes };
+
+    backendApp.CheckForUpdates.mockResolvedValue({
+      success: true,
+      data: {
+        hasUpdate: false,
+        channel: 'latest',
+        currentVersion: '0.8.1',
+        latestVersion: '0.8.1',
+      },
+    });
+
+    const Harness = () => {
+      hook = useAppUpdateManager({
+        runtimeBuildType: 'release',
+        t,
+        onManualCheckHasUpdateRef: openReleaseNotesRef,
+      });
+      return null;
+    };
+
+    act(() => {
+      renderer = create(<Harness />);
+    });
+
+    await act(async () => {
+      await hook?.checkForUpdates(false, true);
+    });
+
+    expect(openReleaseNotes).not.toHaveBeenCalled();
+    expect(hook?.lastUpdateInfo?.hasUpdate).toBe(false);
+    expect(messageApi.success).toHaveBeenCalled();
+  });
+
+  it('does not invoke the manual-check bridge on silent update discovery', async () => {
+    const openReleaseNotes = vi.fn();
+    const openReleaseNotesRef = { current: openReleaseNotes };
+
+    backendApp.CheckForUpdatesSilently.mockResolvedValue({
+      success: true,
+      data: {
+        hasUpdate: true,
+        channel: 'latest',
+        currentVersion: '0.8.1',
+        latestVersion: '0.8.2',
+      },
+    });
+
+    const Harness = () => {
+      hook = useAppUpdateManager({
+        runtimeBuildType: 'release',
+        t,
+        onManualCheckHasUpdateRef: openReleaseNotesRef,
+      });
+      return null;
+    };
+
+    act(() => {
+      renderer = create(<Harness />);
+    });
+
+    await act(async () => {
+      await hook?.checkForUpdates(true);
+    });
+
+    expect(openReleaseNotes).not.toHaveBeenCalled();
+    expect(hook?.lastUpdateInfo?.hasUpdate).toBe(true);
+  });
+
   it('opens the downloaded update directory when a package is already downloaded', async () => {
     backendApp.CheckForUpdates.mockResolvedValue({
       success: true,
diff --git a/frontend/src/hooks/useAppUpdateManager.ts b/frontend/src/hooks/useAppUpdateManager.ts
index dff9be4e..df01c867 100644
--- a/frontend/src/hooks/useAppUpdateManager.ts
+++ b/frontend/src/hooks/useAppUpdateManager.ts
@@ -63,6 +63,8 @@ type UseAppUpdateManagerOptions = {
   runtimeBuildType: string;
   t: Translator;
   updateCenterBridgeRef?: MutableRefObject<UpdateCenterBridge | null>;
+  /** 手动「检查更新」发现新版本时，触发打开更新日志弹窗的桥接回调 */
+  onManualCheckHasUpdateRef?: MutableRefObject<(() => void) | null>;
 };
 
 type AboutInfo = {
@@ -183,6 +185,7 @@ export const useAppUpdateManager = ({
   runtimeBuildType,
   t,
   updateCenterBridgeRef,
+  onManualCheckHasUpdateRef,
 }: UseAppUpdateManagerOptions) => {
   const autoCheckForUpdates = useStore((state) => state.autoCheckForUpdates);
   const autoCheckForUpdatesIntervalMinutes = useStore(
@@ -470,7 +473,7 @@ export const useAppUpdateManager = ({
     void message.success(res?.message || t('app.about.message.install_directory_opened_manual_replace'));
   }, [t]);
 
-  const checkForUpdates = useCallback(async (silent: boolean) => {
+  const checkForUpdates = useCallback(async (silent: boolean, openReleaseNotes = false) => {
     if (updateCheckInFlightRef.current) return;
     updateCheckInFlightRef.current = true;
     setIsCheckingForUpdates(true);
@@ -565,6 +568,11 @@ export const useAppUpdateManager = ({
       if (!silent) {
         void message.info(t('app.about.message.new_version_found', { version: info.latestVersion }));
         setAboutUpdateStatus(statusText);
+        // 仅当显式请求打开更新日志时（如用户点击「检查更新」按钮），才触发弹窗；
+        // 通道切换后的自动复查等场景不传 openReleaseNotes，避免越界打开弹窗（#818）
+        if (openReleaseNotes) {
+          onManualCheckHasUpdateRef?.current?.();
+        }
       }
       if (silent && aboutOpen) {
         setAboutUpdateStatus(statusText);
@@ -598,7 +606,7 @@ export const useAppUpdateManager = ({
     } else {
       setLastUpdateInfo(info);
     }
-  }, [formatAboutUpdateStatus, isUpdateCenterOpen, openUpdateCenter, t]);
+  }, [formatAboutUpdateStatus, isUpdateCenterOpen, onManualCheckHasUpdateRef, openUpdateCenter, t]);
 
   const loadAboutInfo = useCallback(async () => {
     setAboutLoading(true);