diff --git a/src/App.vue b/src/App.vue
index e9d49cb9..8a5ad7e8 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -295,6 +295,7 @@ import {
 } from "./global/downloadStatus";
 import {
   installedSyncEnabled,
+  loadInstalledSyncPreference,
   setInstalledSyncEnabled,
 } from "./global/accountSyncState";
 import {
@@ -336,7 +337,11 @@ import {
   parsePackageArch,
 } from "./modules/appIdentity";
 import { resolveFavoriteItems } from "./modules/favoriteAvailability";
-import { buildSyncItems, cloudItemKey } from "./modules/appListSync";
+import {
+  buildSyncItems,
+  cloudItemKey,
+  mergeInstalledApps,
+} from "./modules/appListSync";
 import type {
   App,
   AppJson,
@@ -441,6 +446,8 @@ const downloadedLoading = ref(false);
 const downloadedError = ref("");
 const downloadedRequestGeneration = ref(0);
 const syncLoading = ref(false);
+const syncRequestGeneration = ref(0);
+const syncCandidateApps = ref<App[]>([]);
 const restoreLoading = ref(false);
 const restoreError = ref("");
 const showRestoreModal = ref(false);
@@ -1477,6 +1484,10 @@ const handleLogout = () => {
   clearFavoriteState();
   clearDownloadedState();
   clearRestoreState();
+  syncRequestGeneration.value += 1;
+  syncLoading.value = false;
+  syncCandidateApps.value = [];
+  loadInstalledSyncPreference(null);
   showLoginModal.value = false;
   showLoginPrompt.value = false;
   isSidebarOpen.value = false;
@@ -1498,6 +1509,7 @@ const handleFlarumLogin = async (payload: FlarumLoginPayload) => {
       flarumToken: flarumToken.token,
     });
     setAuthSession(session);
+    loadInstalledSyncPreference(session.user.id);
     showLoginModal.value = false;
   } catch (error: unknown) {
     loginError.value = (error as Error)?.message || "登录失败，请稍后重试";
@@ -1530,25 +1542,87 @@ const loadDownloadedHistory = async (): Promise<void> => {
 };
 
 const refreshInstalledSyncCandidates = async (): Promise<void> => {
-  await refreshFavoriteInstalledApps();
+  const origins: Array<"spark" | "apm"> = [];
+  if (isOriginEnabled(storeFilter.value, "spark") && sparkAvailable.value) {
+    origins.push("spark");
+  }
+  if (isOriginEnabled(storeFilter.value, "apm") && apmAvailable.value) {
+    origins.push("apm");
+  }
+
+  const refreshedApps: App[] = [];
+  await Promise.all(
+    origins.map(async (origin) => {
+      const pkgnameList =
+        origin === "spark"
+          ? apps.value
+              .filter((app) => app.origin === "spark")
+              .map((app) => app.pkgname)
+          : undefined;
+      const result = await window.ipcRenderer.invoke("list-installed", {
+        origin,
+        pkgnameList,
+      });
+      if (!result?.success) return;
+
+      for (const app of result.apps as InstalledAppInfo[]) {
+        const appInfo = mapInstalledAppToCatalogApp(app, origin);
+        if (appInfo) refreshedApps.push(appInfo);
+      }
+    }),
+  );
+
+  syncCandidateApps.value = mergeInstalledApps(
+    syncCandidateApps.value,
+    refreshedApps,
+    origins,
+  );
 };
 
 const syncInstalledAppsToAccount = async (): Promise<void> => {
   if (!requireLogin("云端同步需要登录星火账号。")) return;
+  if (syncLoading.value) return;
+  const userId = currentUser.value?.id;
+  if (userId === undefined) return;
+  const generation = syncRequestGeneration.value + 1;
+  syncRequestGeneration.value = generation;
   syncLoading.value = true;
   try {
     await refreshInstalledSyncCandidates();
-    const items = buildSyncItems(installedApps.value);
+    if (
+      syncRequestGeneration.value !== generation ||
+      currentUser.value?.id !== userId
+    ) {
+      return;
+    }
+    const items = buildSyncItems(syncCandidateApps.value);
     await uploadSyncedAppList({
       clientArch: window.apm_store.arch || "amd64",
       distro: systemInfo.value.distro,
       items,
     });
+    if (
+      syncRequestGeneration.value !== generation ||
+      currentUser.value?.id !== userId
+    ) {
+      return;
+    }
     downloadedError.value = "";
   } catch (error: unknown) {
+    if (
+      syncRequestGeneration.value !== generation ||
+      currentUser.value?.id !== userId
+    ) {
+      return;
+    }
     downloadedError.value = (error as Error)?.message || "同步已安装应用失败";
   } finally {
-    syncLoading.value = false;
+    if (
+      syncRequestGeneration.value === generation &&
+      currentUser.value?.id === userId
+    ) {
+      syncLoading.value = false;
+    }
   }
 };
 
@@ -2215,6 +2289,19 @@ onUnmounted(() => {
 });
 
 // 观察器
+watch(
+  () => currentUser.value?.id ?? null,
+  (userId, previousUserId) => {
+    loadInstalledSyncPreference(userId);
+    if (previousUserId !== undefined && userId !== previousUserId) {
+      syncRequestGeneration.value += 1;
+      syncLoading.value = false;
+      syncCandidateApps.value = [];
+    }
+  },
+  { immediate: true },
+);
+
 watch(themeMode, (newVal) => {
   localStorage.setItem("theme", newVal);
   window.ipcRenderer.send(
diff --git a/src/__tests__/unit/App.account-placeholders.test.ts b/src/__tests__/unit/App.account-placeholders.test.ts
index 932d6d61..bcea8572 100644
--- a/src/__tests__/unit/App.account-placeholders.test.ts
+++ b/src/__tests__/unit/App.account-placeholders.test.ts
@@ -1,4 +1,10 @@
-import { fireEvent, render, screen, waitFor } from "@testing-library/vue";
+import {
+  fireEvent,
+  render,
+  screen,
+  waitFor,
+  within,
+} from "@testing-library/vue";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 
 import App from "@/App.vue";
@@ -6,12 +12,14 @@ import {
   fetchSyncedAppList,
   listDownloadedApps,
   listFavoriteFolders,
+  uploadSyncedAppList,
 } from "@/modules/backendApi";
 import { setAuthSession } from "@/global/authState";
 import type {
   DownloadedAppList,
   FavoriteFolder,
   FavoriteItem,
+  SyncedAppList,
 } from "@/global/typedefinition";
 
 const invoke = vi.fn();
@@ -56,6 +64,14 @@ const downloadedList = (
   pageSize: 50,
 });
 
+const syncedList = (items: SyncedAppList["items"]): SyncedAppList => ({
+  snapshotName: "默认列表",
+  clientArch: "amd64",
+  distro: "deepin 25",
+  updatedAt: "2026-05-18T00:00:00Z",
+  items,
+});
+
 const setSecondUserSession = () => {
   setAuthSession({
     accessToken: "backend-token-b",
@@ -153,6 +169,7 @@ vi.mock("@/modules/backendApi", () => ({
 
 describe("App account placeholders", () => {
   beforeEach(() => {
+    vi.clearAllMocks();
     invoke.mockReset();
     invoke.mockImplementation(async (channel: string) => {
       if (channel === "get-store-filter") return "both";
@@ -492,4 +509,78 @@ describe("App account placeholders", () => {
       );
     });
   });
+
+  it("keeps the installed modal scoped to the active origin after sync", async () => {
+    invoke.mockImplementation(async (channel: string, payload?: unknown) => {
+      if (channel === "get-store-filter") return "both";
+      if (channel === "check-spark-available") return true;
+      if (channel === "check-apm-available") return true;
+      if (channel === "get-app-version") return "5.0.0";
+      if (channel === "get-system-info") return { distro: "deepin 25" };
+      if (channel === "list-installed") {
+        const request = payload as { origin?: string };
+        if (request.origin === "spark") {
+          return {
+            success: true,
+            apps: [
+              {
+                pkgname: "wps",
+                name: "WPS",
+                version: "1.0.0",
+                arch: "amd64",
+                flags: "installed",
+                origin: "spark",
+              },
+            ],
+          };
+        }
+        return { success: true, apps: [] };
+      }
+      return [];
+    });
+    vi.mocked(uploadSyncedAppList).mockResolvedValueOnce(syncedList([]));
+    render(App);
+
+    await fireEvent.click(await screen.findByText("应用管理"));
+    const modal = screen.getByText("已安装应用").closest(".fixed");
+    if (!(modal instanceof HTMLElement)) throw new Error("modal not found");
+    expect(within(modal).getByText("暂无已安装应用")).toBeTruthy();
+
+    await fireEvent.click(
+      within(modal).getByRole("button", { name: /同步到账号/ }),
+    );
+
+    await waitFor(() => {
+      expect(uploadSyncedAppList).toHaveBeenCalled();
+    });
+    expect(within(modal).queryByText("WPS")).toBeNull();
+    expect(within(modal).getByText("暂无已安装应用")).toBeTruthy();
+  });
+
+  it("ignores overlapping installed sync requests", async () => {
+    const syncUpload = createDeferred<SyncedAppList>();
+    vi.mocked(uploadSyncedAppList).mockReturnValue(syncUpload.promise);
+    invoke.mockImplementation(async (channel: string) => {
+      if (channel === "get-store-filter") return "apm";
+      if (channel === "check-spark-available") return false;
+      if (channel === "check-apm-available") return true;
+      if (channel === "get-app-version") return "5.0.0";
+      if (channel === "get-system-info") return { distro: "deepin 25" };
+      if (channel === "list-installed") return { success: true, apps: [] };
+      return [];
+    });
+    render(App);
+
+    await fireEvent.click(await screen.findByRole("button", { name: /Momen/ }));
+    await fireEvent.click(screen.getByText("用户管理"));
+    await fireEvent.click(
+      await screen.findByRole("button", { name: "立即同步" }),
+    );
+    await fireEvent.click(screen.getByRole("button", { name: "立即同步" }));
+
+    await waitFor(() => {
+      expect(uploadSyncedAppList).toHaveBeenCalledTimes(1);
+    });
+    syncUpload.resolve(syncedList([]));
+  });
 });
diff --git a/src/__tests__/unit/accountSyncState.test.ts b/src/__tests__/unit/accountSyncState.test.ts
new file mode 100644
index 00000000..8d7b2fd8
--- /dev/null
+++ b/src/__tests__/unit/accountSyncState.test.ts
@@ -0,0 +1,28 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+describe("accountSyncState", () => {
+  beforeEach(() => {
+    vi.resetModules();
+    localStorage.clear();
+  });
+
+  it("scopes installed sync preference to the current user", async () => {
+    const {
+      installedSyncEnabled,
+      loadInstalledSyncPreference,
+      setInstalledSyncEnabled,
+    } = await import("@/global/accountSyncState");
+
+    loadInstalledSyncPreference(1);
+    setInstalledSyncEnabled(true);
+
+    loadInstalledSyncPreference(2);
+
+    expect(installedSyncEnabled.value).toBeNull();
+
+    setInstalledSyncEnabled(false);
+    loadInstalledSyncPreference(1);
+
+    expect(installedSyncEnabled.value).toBe(true);
+  });
+});
diff --git a/src/__tests__/unit/appListSync.test.ts b/src/__tests__/unit/appListSync.test.ts
index 988e438b..c567339d 100644
--- a/src/__tests__/unit/appListSync.test.ts
+++ b/src/__tests__/unit/appListSync.test.ts
@@ -1,6 +1,10 @@
 import { describe, expect, it } from "vitest";
 
-import { buildSyncItems, cloudItemKey } from "@/modules/appListSync";
+import {
+  buildSyncItems,
+  cloudItemKey,
+  mergeInstalledApps,
+} from "@/modules/appListSync";
 import type { App } from "@/global/typedefinition";
 
 const createApp = (overrides: Partial<App> = {}): App => ({
@@ -71,4 +75,19 @@ describe("appListSync", () => {
       "apm:amber-ce",
     );
   });
+
+  it("merges refreshed apps without mutating active modal origin lists", () => {
+    const current = [createApp({ origin: "apm", pkgname: "apm-installed" })];
+    const refreshed = [
+      createApp({ origin: "spark", pkgname: "spark-installed" }),
+    ];
+
+    expect(mergeInstalledApps(current, refreshed, ["spark"])).toEqual([
+      expect.objectContaining({ origin: "apm", pkgname: "apm-installed" }),
+      expect.objectContaining({ origin: "spark", pkgname: "spark-installed" }),
+    ]);
+    expect(current).toEqual([
+      expect.objectContaining({ origin: "apm", pkgname: "apm-installed" }),
+    ]);
+  });
 });
diff --git a/src/global/accountSyncState.ts b/src/global/accountSyncState.ts
index acb0846e..7b7d2958 100644
--- a/src/global/accountSyncState.ts
+++ b/src/global/accountSyncState.ts
@@ -1,26 +1,39 @@
 import { ref, watch } from "vue";
 
 const INSTALLED_SYNC_STORAGE_KEY = "spark-store-installed-sync-enabled";
+let activeSyncUserId: number | null = null;
 
-const readSyncEnabled = (): boolean | null => {
-  const savedValue = localStorage.getItem(INSTALLED_SYNC_STORAGE_KEY);
+const syncStorageKey = (userId: number | null): string =>
+  userId === null
+    ? INSTALLED_SYNC_STORAGE_KEY
+    : `${INSTALLED_SYNC_STORAGE_KEY}:${userId}`;
+
+const readSyncEnabled = (userId: number | null): boolean | null => {
+  const savedValue = localStorage.getItem(syncStorageKey(userId));
   if (savedValue === "true") return true;
   if (savedValue === "false") return false;
   return null;
 };
 
-export const installedSyncEnabled = ref<boolean | null>(readSyncEnabled());
+export const installedSyncEnabled = ref<boolean | null>(
+  readSyncEnabled(activeSyncUserId),
+);
+
+export const loadInstalledSyncPreference = (userId: number | null): void => {
+  activeSyncUserId = userId;
+  installedSyncEnabled.value = readSyncEnabled(userId);
+};
 
 export const setInstalledSyncEnabled = (enabled: boolean): void => {
   installedSyncEnabled.value = enabled;
-  localStorage.setItem(INSTALLED_SYNC_STORAGE_KEY, String(enabled));
+  localStorage.setItem(syncStorageKey(activeSyncUserId), String(enabled));
 };
 
 watch(installedSyncEnabled, (enabled) => {
   if (enabled === null) {
-    localStorage.removeItem(INSTALLED_SYNC_STORAGE_KEY);
+    localStorage.removeItem(syncStorageKey(activeSyncUserId));
     return;
   }
 
-  localStorage.setItem(INSTALLED_SYNC_STORAGE_KEY, String(enabled));
+  localStorage.setItem(syncStorageKey(activeSyncUserId), String(enabled));
 });
diff --git a/src/modules/appListSync.ts b/src/modules/appListSync.ts
index 6e26f78a..86d144de 100644
--- a/src/modules/appListSync.ts
+++ b/src/modules/appListSync.ts
@@ -28,3 +28,22 @@ export const buildSyncItems = (apps: App[]): SyncedAppListItem[] => {
 export const cloudItemKey = (
   item: Pick<SyncedAppListItem, "origin" | "pkgname">,
 ): string => `${item.origin}:${item.pkgname}`;
+
+export const mergeInstalledApps = (
+  currentApps: App[],
+  refreshedApps: App[],
+  refreshedOrigins: Array<"spark" | "apm">,
+): App[] => {
+  const refreshedKeys = new Set(
+    refreshedApps.map((app) => `${app.origin}:${app.pkgname}`),
+  );
+
+  return [
+    ...currentApps.filter(
+      (app) =>
+        !refreshedOrigins.includes(app.origin) &&
+        !refreshedKeys.has(`${app.origin}:${app.pkgname}`),
+    ),
+    ...refreshedApps,
+  ];
+};