diff --git a/backend/app/routers.py b/backend/app/routers.py
index 53dd9ce..86a470d 100644
--- a/backend/app/routers.py
+++ b/backend/app/routers.py
@@ -480,6 +480,8 @@ _VALID_DISPLAY_ACTIONS = {
     "voice_start", "voice_stop", "voice_refresh",
     # 媒体
     "play", "pause", "next", "prev", "set_mode", "play_target",
+    # 双屏
+    "dual_screen",
     # 全局
     "alert", "show_card", "minimize", "settings_changed", "playlist_changed",
 }
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index ad3e6ae..02acfd9 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -24,15 +24,17 @@ fn set_dual_screen(app: AppHandle, on: bool) -> Result<String, String> {
         let _ = w.set_focus();
         return Ok("on".into());
     }
-    let mut builder = WebviewWindowBuilder::new(&app, "secondary", WebviewUrl::App("/".into()))
+    let mut builder = WebviewWindowBuilder::new(&app, "secondary", WebviewUrl::default())
         .title("OPC 运营中心 · 双屏");
     // 定位到第二块屏（非主屏；无第二屏则用第一块）
     if let Ok(monitors) = app.available_monitors() {
+        eprintln!("[dual] available_monitors={}", monitors.len());
         let primary_pos = app
             .primary_monitor()
             .ok()
             .flatten()
             .map(|pm| { let p = pm.position(); (p.x, p.y) });
+        eprintln!("[dual] primary_pos={:?}", primary_pos);
         let target = monitors
             .iter()
             .find(|m| { let p = m.position(); Some((p.x, p.y)) != primary_pos })
@@ -40,11 +42,18 @@ fn set_dual_screen(app: AppHandle, on: bool) -> Result<String, String> {
         if let Some(mon) = target {
             let p = mon.position();
             let s = mon.size();
+            eprintln!("[dual] target {}x{} @ {},{}", s.width, s.height, p.x, p.y);
             builder = builder.position(p.x as f64, p.y as f64).inner_size(s.width as f64, s.height as f64);
         }
     }
     let win = builder.build().map_err(|e| e.to_string())?;
-    let _ = win.set_fullscreen(true);
+    // 等窗口内容就绪后再全屏（避免过早全屏导致白屏/布局异常）
+    let win2 = win.clone();
+    std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(400));
+        let _ = win2.set_fullscreen(true);
+        let _ = win2.set_focus();
+    });
     Ok("on".into())
 }
 
diff --git a/src/components/ErrorBoundary.jsx b/src/components/ErrorBoundary.jsx
new file mode 100644
index 0000000..8dff8b5
--- /dev/null
+++ b/src/components/ErrorBoundary.jsx
@@ -0,0 +1,35 @@
+import { Component } from 'react';
+
+/* 全局错误边界：渲染崩溃时不白屏，显示具体错误 + 重载按钮，便于双屏/异常定位 */
+export default class ErrorBoundary extends Component {
+  constructor(props) {
+    super(props);
+    this.state = { err: null };
+  }
+  static getDerivedStateFromError(err) {
+    return { err };
+  }
+  componentDidCatch(err, info) {
+    // eslint-disable-next-line no-console
+    console.error('[AppError]', err, info);
+  }
+  render() {
+    if (this.state.err) {
+      return (
+        <div style={{ padding: 40, fontFamily: 'sans-serif', color: '#333' }}>
+          <h3>页面加载出错</h3>
+          <pre style={{ whiteSpace: 'pre-wrap', fontSize: 12, background: '#f5f5f5', padding: 12, borderRadius: 8 }}>
+            {String(this.state.err && (this.state.err.message || this.state.err))}
+          </pre>
+          <button
+            style={{ marginTop: 12, padding: '8px 16px', cursor: 'pointer' }}
+            onClick={() => { this.setState({ err: null }); window.location.reload(); }}
+          >
+            重载
+          </button>
+        </div>
+      );
+    }
+    return this.props.children;
+  }
+}
diff --git a/src/main.jsx b/src/main.jsx
index 00e94d7..f14ce1d 100644
--- a/src/main.jsx
+++ b/src/main.jsx
@@ -1,6 +1,7 @@
 import React from "react";
 import ReactDOM from "react-dom/client";
 import App from "./App";
+import ErrorBoundary from "./components/ErrorBoundary";
 import { ThemeProvider } from "@appica/ui-react/providers/theme-provider";
 import { getApiBase } from "./config";
 import { invoke } from "@tauri-apps/api/core";
@@ -60,9 +61,11 @@ async function bootstrapRuntimeConfig() {
 bootstrapRuntimeConfig().then(() => {
   ReactDOM.createRoot(document.getElementById("root")).render(
     <React.StrictMode>
-      <ThemeProvider>
-        <App />
-      </ThemeProvider>
+      <ErrorBoundary>
+        <ThemeProvider>
+          <App />
+        </ThemeProvider>
+      </ErrorBoundary>
     </React.StrictMode>,
   );
 });