diff --git a/apps/desktop/src/main/index.mjs b/apps/desktop/src/main/index.mjs
index ca7320d8..a9fe6f03 100644
--- a/apps/desktop/src/main/index.mjs
+++ b/apps/desktop/src/main/index.mjs
@@ -29,7 +29,7 @@ import { isAllowedPrintPreviewUrl } from "./window-open-policy.mjs";
 import { showWindow } from "./window-visibility.mjs";
 import { trayIconPath } from "./tray-icon.mjs";
 import { writeRichClipboard } from "./clipboard-write.mjs";
-import { captureScreenToNote, screenshotImportIpcPayload, writeScreenshotTempPath } from "./screenshot-capture.mjs";
+import { captureScreenToNote, createScreenshotCaptureGuard, screenshotImportIpcPayload, writeScreenshotTempPath } from "./screenshot-capture.mjs";
 import { LocalDataResetError, scheduleMacLocalDataReset } from "./local-data-reset.mjs";
 import { buildDesktopDiagnosticIssueUrl, normalizeDesktopDiagnostic } from "./desktop-diagnostics.mjs";
 import { createRendererStartupGuard } from "./renderer-startup-guard.mjs";
@@ -508,7 +508,7 @@ const importMarkdownFile = async (filePath) => {
 
 let pendingMarkdownImport = null;
 let pendingScreenshotImport = null;
-let screenshotCaptureInFlight = false;
+const screenshotCaptureGuard = createScreenshotCaptureGuard();
 let rendererReady = false;
 
 const flushPendingMarkdownImport = () => {
@@ -525,6 +525,7 @@ const sendScreenshotImport = (payload) => {
     pendingScreenshotImport = ipcPayload;
     return;
   }
+  pendingScreenshotImport = null;
   mainWindow.webContents.send("desktop:import-screenshot", ipcPayload);
 };
 
@@ -537,8 +538,7 @@ const flushPendingScreenshotImport = () => {
 };
 
 const captureScreenshotToNote = async () => {
-  if (screenshotCaptureInFlight) return;
-  screenshotCaptureInFlight = true;
+  if (!screenshotCaptureGuard.tryBegin()) return;
   const copy = desktopMenuCopy(app.getLocale());
   const wasVisible = Boolean(mainWindow && !mainWindow.isDestroyed() && mainWindow.isVisible());
   const revealWindow = () => {
@@ -572,7 +572,7 @@ const captureScreenshotToNote = async () => {
       message: copy.screenshotFailed,
     });
   } finally {
-    screenshotCaptureInFlight = false;
+    screenshotCaptureGuard.end();
   }
 };
 
diff --git a/apps/desktop/src/main/screenshot-capture.mjs b/apps/desktop/src/main/screenshot-capture.mjs
index ae3f6306..ccab1c07 100644
--- a/apps/desktop/src/main/screenshot-capture.mjs
+++ b/apps/desktop/src/main/screenshot-capture.mjs
@@ -37,6 +37,38 @@ export const screenshotImportIpcPayload = (captured) => ({
   bytes: normalizeIpcBytes(captured.bytes),
 });
 
+// Full-screen capture finishes in a few hundred milliseconds. macOS/Electron
+// tray menus can deliver the same click twice after that, so keep the capture
+// locked through a short cooldown instead of releasing it in the same tick.
+export const SCREENSHOT_CAPTURE_COOLDOWN_MS = 2000;
+
+export const createScreenshotCaptureGuard = ({
+  cooldownMs = SCREENSHOT_CAPTURE_COOLDOWN_MS,
+  schedule = setTimeout,
+  cancel = clearTimeout,
+} = {}) => {
+  let inFlight = false;
+  let cooldownTimer = null;
+  return {
+    tryBegin() {
+      if (inFlight) return false;
+      inFlight = true;
+      if (cooldownTimer != null) {
+        cancel(cooldownTimer);
+        cooldownTimer = null;
+      }
+      return true;
+    },
+    end() {
+      if (cooldownTimer != null) cancel(cooldownTimer);
+      cooldownTimer = schedule(() => {
+        inFlight = false;
+        cooldownTimer = null;
+      }, cooldownMs);
+    },
+  };
+};
+
 export const isChineseDesktopLocale = (locale) =>
   typeof locale === "string" && locale.toLowerCase().startsWith("zh");
 
diff --git a/apps/desktop/src/main/screenshot-capture.test.mjs b/apps/desktop/src/main/screenshot-capture.test.mjs
index 90860e55..2d16f4b2 100644
--- a/apps/desktop/src/main/screenshot-capture.test.mjs
+++ b/apps/desktop/src/main/screenshot-capture.test.mjs
@@ -2,6 +2,7 @@ import { describe, expect, test } from "bun:test";
 import { readFileSync } from "node:fs";
 import {
   captureDisplayScreenshot,
+  createScreenshotCaptureGuard,
   isScreenshotCancelledExit,
   macScreencaptureArgs,
   normalizeIpcBytes,
@@ -85,18 +86,42 @@ describe("screenshot capture helpers", () => {
   });
 });
 
+describe("screenshot capture guard", () => {
+  test("rejects a second capture until the cooldown elapses", () => {
+    const timers = [];
+    const guard = createScreenshotCaptureGuard({
+      cooldownMs: 20,
+      schedule: (fn) => {
+        timers.push(fn);
+        return timers.length;
+      },
+      cancel: () => {},
+    });
+    expect(guard.tryBegin()).toBe(true);
+    expect(guard.tryBegin()).toBe(false);
+    guard.end();
+    expect(guard.tryBegin()).toBe(false);
+    timers.at(-1)();
+    expect(guard.tryBegin()).toBe(true);
+  });
+});
+
 describe("desktop screenshot to note wiring", () => {
   test("replaces the tray sync and backup actions with screenshot capture", () => {
     expect(mainSource).toContain("captureScreenshotToNote");
     expect(mainSource).toContain("captureScreenToNote");
+    expect(mainSource).toContain("createScreenshotCaptureGuard");
+    expect(mainSource).toContain("pendingScreenshotImport = null");
     expect(mainSource).not.toContain("overlay.html");
     expect(mainSource).toContain("copy.screenshotToNote");
     expect(mainSource).not.toContain('label: copy.syncNow, click: () => sendDesktopCommand("sync-now")');
     expect(mainSource).not.toContain('label: copy.backupNow, click: () => sendDesktopCommand("backup-now")');
     expect(preloadSource).toContain("onImportScreenshot");
+    expect(preloadSource).toContain("screenshotImportListener");
     expect(preloadSource).toContain('value.type === "Buffer"');
     expect(workspaceSource).toContain("onImportScreenshot");
     expect(workspaceSource).toContain("createScreenshotMemo");
+    expect(workspaceSource).toContain("screenshotImportGate");
     expect(workspaceSource).toContain("screenshotFileFromImportPayload");
     expect(workspaceSource).not.toContain("setPendingEditorInsert");
   });
diff --git a/apps/desktop/src/preload/index.cjs b/apps/desktop/src/preload/index.cjs
index f42520f8..29c3300f 100644
--- a/apps/desktop/src/preload/index.cjs
+++ b/apps/desktop/src/preload/index.cjs
@@ -21,6 +21,8 @@ const normalizeIpcBytes = (value) => {
   return new Uint8Array();
 };
 
+let screenshotImportListener = null;
+
 contextBridge.exposeInMainWorld("edgeeverDesktop", Object.freeze({
   isAvailable: true,
   canClearLocalData: ipcRenderer.sendSync("desktop:local-data-reset-available-sync"),
@@ -86,10 +88,17 @@ contextBridge.exposeInMainWorld("edgeeverDesktop", Object.freeze({
     return () => ipcRenderer.removeListener("desktop:import-markdown", listener);
   },
   onImportScreenshot: (callback) => {
+    if (screenshotImportListener) {
+      ipcRenderer.removeListener("desktop:import-screenshot", screenshotImportListener);
+    }
     const listener = (_event, payload) => {
       callback({ ...payload, bytes: normalizeIpcBytes(payload?.bytes) });
     };
+    screenshotImportListener = listener;
     ipcRenderer.on("desktop:import-screenshot", listener);
-    return () => ipcRenderer.removeListener("desktop:import-screenshot", listener);
+    return () => {
+      ipcRenderer.removeListener("desktop:import-screenshot", listener);
+      if (screenshotImportListener === listener) screenshotImportListener = null;
+    };
   },
 }));
diff --git a/apps/web/src/lib/screenshot-import.test.mjs b/apps/web/src/lib/screenshot-import.test.mjs
index 573fff16..fb979dae 100644
--- a/apps/web/src/lib/screenshot-import.test.mjs
+++ b/apps/web/src/lib/screenshot-import.test.mjs
@@ -1,8 +1,10 @@
 import { describe, expect, test } from "bun:test";
 import {
+  createScreenshotImportGate,
   createScreenshotMemo,
   normalizeScreenshotBytes,
   screenshotFileFromImportPayload,
+  screenshotImportDedupeKey,
   screenshotNoteContent,
 } from "./screenshot-import.ts";
 
@@ -120,3 +122,37 @@ describe("screenshot note content", () => {
     expect(deleted).toEqual(["memo_failed"]);
   });
 });
+
+describe("screenshot import gate", () => {
+  test("builds a stable key from the title, filename, and byte length", () => {
+    expect(screenshotImportDedupeKey({
+      name: "screenshot-20260915-222604.png",
+      title: "截图 2026-09-15 22:26",
+      bytes: new Uint8Array(4),
+    })).toBe(["截图 2026-09-15 22:26", "screenshot-20260915-222604.png", "4"].join("\u0000"));
+  });
+
+  test("drops a second import while the first screenshot is still being saved", () => {
+    const gate = createScreenshotImportGate(1000);
+    expect(gate.tryBegin("a")).toBe(true);
+    expect(gate.tryBegin("a")).toBe(false);
+    expect(gate.tryBegin("b")).toBe(false);
+  });
+
+  test("ignores the same screenshot payload during the cooldown after a successful import", () => {
+    const gate = createScreenshotImportGate(1000);
+    expect(gate.tryBegin("a")).toBe(true);
+    gate.finish("a", 0);
+    expect(gate.tryBegin("a", 500)).toBe(false);
+    expect(gate.tryBegin("b", 500)).toBe(true);
+    gate.fail("b");
+    expect(gate.tryBegin("a", 1500)).toBe(true);
+  });
+
+  test("allows a retry after a failed import", () => {
+    const gate = createScreenshotImportGate(1000);
+    expect(gate.tryBegin("a")).toBe(true);
+    gate.fail("a");
+    expect(gate.tryBegin("a")).toBe(true);
+  });
+});
diff --git a/apps/web/src/lib/screenshot-import.ts b/apps/web/src/lib/screenshot-import.ts
index 567c6940..60a9b9e2 100644
--- a/apps/web/src/lib/screenshot-import.ts
+++ b/apps/web/src/lib/screenshot-import.ts
@@ -32,6 +32,36 @@ export const screenshotFileFromImportPayload = (payload: {
   return new File([blobPart], payload.name || "screenshot.png", { type: payload.type || "image/png" });
 };
 
+export const screenshotImportDedupeKey = (payload: {
+  name?: string;
+  title?: string;
+  bytes?: { byteLength?: number } | null;
+}) => [payload.title?.trim() || "", payload.name || "", String(payload.bytes?.byteLength ?? 0)].join("\u0000");
+
+export const createScreenshotImportGate = (cooldownMs = 2000) => {
+  let inFlightKey: string | null = null;
+  let lastKey: string | null = null;
+  let lastAt = 0;
+  return {
+    tryBegin(key: string, now = Date.now()) {
+      if (inFlightKey) return false;
+      if (lastKey === key && now - lastAt < cooldownMs) return false;
+      inFlightKey = key;
+      return true;
+    },
+    finish(key: string, now = Date.now()) {
+      if (inFlightKey === key) inFlightKey = null;
+      lastKey = key;
+      lastAt = now;
+    },
+    fail(key: string) {
+      if (inFlightKey === key) inFlightKey = null;
+    },
+  };
+};
+
+export const screenshotImportGate = createScreenshotImportGate();
+
 const escapeMarkdownImageAlt = (value: string) => value.replaceAll("\\", "\\\\").replaceAll("]", "\\]");
 
 export const screenshotNoteContent = (filename: string, url: string) => {