diff --git a/src/main/desktop-pick.ts b/src/main/desktop-pick.ts
index 769bfb6..0637e82 100644
--- a/src/main/desktop-pick.ts
+++ b/src/main/desktop-pick.ts
@@ -706,10 +706,10 @@ function regionOverlayHtml(): string {
     "<div id=sel></div><div id=tip>拖拽框选区域，松开鼠标完成；Esc 取消</div>",
     "<script>",
     "var sel = document.getElementById('sel'); var start = null;",
-    "document.addEventListener('mousedown', function(e) { start = [e.clientX, e.clientY]; sel.style.display = 'block'; sel.style.left = e.clientX + 'px'; sel.style.top = e.clientY + 'px'; sel.style.width = '0px'; sel.style.height = '0px'; });",
+    "document.addEventListener('mousedown', function(e) { start = [e.clientX, e.clientY]; window.__down = true; window.__wasDown = true; sel.style.display = 'block'; sel.style.left = e.clientX + 'px'; sel.style.top = e.clientY + 'px'; sel.style.width = '0px'; sel.style.height = '0px'; });",
     "document.addEventListener('mousemove', function(e) { if (!start) return; sel.style.left = Math.min(start[0], e.clientX) + 'px'; sel.style.top = Math.min(start[1], e.clientY) + 'px'; sel.style.width = Math.abs(e.clientX - start[0]) + 'px'; sel.style.height = Math.abs(e.clientY - start[1]) + 'px'; });",
-    "document.addEventListener('mouseup', function(e) { if (!start) return; window.__region = { x: Math.min(start[0], e.clientX), y: Math.min(start[1], e.clientY), width: Math.abs(e.clientX - start[0]), height: Math.abs(e.clientY - start[1]) }; window.__done = true; });",
-    "document.addEventListener('keydown', function(e) { if (e.key === 'Escape') { window.__cancelled = true; window.__done = true; } });",
+    "document.addEventListener('mouseup', function() { if (!start) return; start = null; window.__down = false; });",
+    "document.addEventListener('keydown', function(e) { if (e.key === 'Escape') { window.__cancelled = true; } });",
     "</script></body></html>"
   ].join("");
 }
@@ -735,34 +735,47 @@ export async function pickScreenRegion(): Promise<{ x: number; y: number; width:
   });
   const deadline = Date.now() + 60000;
   let cancelled = false;
-  let picked: { region: { x: number; y: number; width: number; height: number }; display: (typeof displays)[number] } | null = null;
+  // 选区坐标不取自窗口 clientX/clientY(混合 DPI 下窗口坐标映射不可靠),
+  // 渲染层只上报按下/松开状态, 主进程用 getCursorScreenPoint 采样鼠标屏幕绝对 DIP 坐标
+  let downPoint: { x: number; y: number } | null = null;
+  let sawDown = false;
+  let picked: { rect: { x: number; y: number; width: number; height: number }; display: (typeof displays)[number] } | null = null;
   while (Date.now() < deadline) {
-    await new Promise(r => setTimeout(r, 250));
-    for (const { win, display } of overlays) {
+    await new Promise(r => setTimeout(r, 100));
+    let state: { down: boolean; wasDown: boolean; cancelled: boolean } | null = null;
+    for (const { win } of overlays) {
       if (win.isDestroyed()) continue;
       try {
-        const state = await win.webContents.executeJavaScript("JSON.stringify({ done: window.__done === true, cancelled: window.__cancelled === true, region: window.__region || null })", true);
-        const parsed = JSON.parse(state) as { done: boolean; cancelled: boolean; region: { x: number; y: number; width: number; height: number } | null };
-        if (parsed.cancelled) { cancelled = true; break; }
-        if (parsed.done && parsed.region && parsed.region.width > 2 && parsed.region.height > 2) {
-          picked = { region: parsed.region, display };
-          break;
-        }
+        const raw = await win.webContents.executeJavaScript("JSON.stringify({ down: !!window.__down, wasDown: !!window.__wasDown, cancelled: !!window.__cancelled })", true);
+        state = JSON.parse(raw) as { down: boolean; wasDown: boolean; cancelled: boolean };
+        break;
       } catch {}
     }
-    if (cancelled || picked) break;
+    if (!state) continue;
+    if (state.cancelled) { cancelled = true; break; }
+    const cursor = screen.getCursorScreenPoint();
+    if (state.down && !downPoint) { downPoint = { x: cursor.x, y: cursor.y }; sawDown = true; }
+    if (!state.down && sawDown && downPoint) {
+      const display = displayForPoint(downPoint.x, downPoint.y);
+      const rx0 = Math.min(downPoint.x, cursor.x);
+      const ry0 = Math.min(downPoint.y, cursor.y);
+      const rx1 = Math.max(downPoint.x, cursor.x);
+      const ry1 = Math.max(downPoint.y, cursor.y);
+      picked = { rect: { x: rx0, y: ry0, width: rx1 - rx0, height: ry1 - ry0 }, display };
+      break;
+    }
   }
   for (const w of appWindows) { if (!w.isDestroyed()) { w.show(); w.restore(); w.focus(); } }
   for (const { win } of overlays) if (!win.isDestroyed()) win.destroy();
   if (cancelled) throw new RuntimeError("pick_cancelled", "已取消框选");
-  if (!picked) throw new RuntimeError("pick_cancelled", "未完成框选");
-  const { region, display } = picked;
+  if (!picked || picked.rect.width <= 2 || picked.rect.height <= 2) throw new RuntimeError("pick_cancelled", "未完成框选");
+  const { rect, display } = picked;
   await new Promise(r => setTimeout(r, 300));
   const outDir = path.join(app.getPath("userData"), "region-picks");
   fs.mkdirSync(outDir, { recursive: true });
   const imagePath = path.join(outDir, `pick-region-${Date.now()}.png`);
   // GDI CopyFromScreen 截不到 GPU 合成窗口(Electron 自身界面), 会截出全黑;
-  // 改用 desktopCapturer 走系统合成器截屏。覆盖层坐标是本屏 DIP, 裁剪时按 scaleFactor 换算物理像素
+  // 改用 desktopCapturer 走系统合成器截屏。rect 是屏幕绝对 DIP, 裁剪时换算到该屏相对坐标再乘 scaleFactor
   const scale = display.scaleFactor || 1;
   const sources = await desktopCapturer.getSources({
     types: ["screen"],
@@ -776,17 +789,19 @@ export async function pickScreenRegion(): Promise<{ x: number; y: number; width:
   }
   const thumbnail = source.thumbnail;
   const actualScale = thumbnail.getSize().width / Math.max(1, display.bounds.width);
-  const cropX = Math.max(0, Math.min(thumbnail.getSize().width - 1, Math.round(region.x * actualScale)));
-  const cropY = Math.max(0, Math.min(thumbnail.getSize().height - 1, Math.round(region.y * actualScale)));
-  const cropW = Math.max(1, Math.min(thumbnail.getSize().width - cropX, Math.round(region.width * actualScale)));
-  const cropH = Math.max(1, Math.min(thumbnail.getSize().height - cropY, Math.round(region.height * actualScale)));
+  const relX = rect.x - display.bounds.x;
+  const relY = rect.y - display.bounds.y;
+  const cropX = Math.max(0, Math.min(thumbnail.getSize().width - 1, Math.round(relX * actualScale)));
+  const cropY = Math.max(0, Math.min(thumbnail.getSize().height - 1, Math.round(relY * actualScale)));
+  const cropW = Math.max(1, Math.min(thumbnail.getSize().width - cropX, Math.round(rect.width * actualScale)));
+  const cropH = Math.max(1, Math.min(thumbnail.getSize().height - cropY, Math.round(rect.height * actualScale)));
   fs.writeFileSync(imagePath, thumbnail.crop({ x: cropX, y: cropY, width: cropW, height: cropH }).toPNG());
   // 返回屏幕绝对 DIP 坐标(含负值/副屏偏移)+该屏缩放比, 运行时由此换算点击位置
   return {
-    x: display.bounds.x + region.x,
-    y: display.bounds.y + region.y,
-    width: region.width,
-    height: region.height,
+    x: rect.x,
+    y: rect.y,
+    width: rect.width,
+    height: rect.height,
     scale,
     imagePath
   };