diff --git a/src/app/background/index.ts b/src/app/background/index.ts
index 9f6dd27..bf308f9 100644
--- a/src/app/background/index.ts
+++ b/src/app/background/index.ts
@@ -169,6 +169,8 @@ async function handleRequest(request: ExtensionRequest, sender: Browser.runtime.
         'yakit.browser_authorization.open',
         request.payload,
       ));
+    case 'authorization.yakit.instances':
+      return ok(await engineBridge.requestEngine('yakit.browser_authorization.instances', {}));
     case 'context.capture': {
       const { tabId, frameId, documentId, ...options } = request.payload;
       const target = await requiredRequestTarget({ tabId, frameId, documentId }, sender);
diff --git a/src/features/authorization-testing/ui/AuthorizationTestingWorkspace.tsx b/src/features/authorization-testing/ui/AuthorizationTestingWorkspace.tsx
index 755ef61..95ab0a7 100644
--- a/src/features/authorization-testing/ui/AuthorizationTestingWorkspace.tsx
+++ b/src/features/authorization-testing/ui/AuthorizationTestingWorkspace.tsx
@@ -8,7 +8,7 @@ import { Button } from '@/components/ui/button';
 import { authorizationShareGrantInput } from '@/features/grants/gateway-share';
 import { errorMessage, request } from '@/platform/messaging/runtime';
 import type {
-  ActiveTabInfo, BridgeStatus, BrowserIsolationContext, BrowserIsolationInspection,
+  ActiveTabInfo, BridgeStatus, BrowserAuthorizationInstance, BrowserIsolationContext, BrowserIsolationInspection,
   ExtensionState, NetworkCaptureStatus,
 } from '@/types/models';
 import {
@@ -247,6 +247,8 @@ export function AuthorizationTestingWorkspace({
   const [localError, setLocalError] = useState('');
   const [identityNotice, setIdentityNotice] = useState('');
   const [clock, setClock] = useState(Date.now());
+  const [browserInstances, setBrowserInstances] = useState<BrowserAuthorizationInstance[]>([]);
+  const [targetDeviceId, setTargetDeviceId] = useState('');
 
   const leftTab = eligibleTabs.find((item) => item.id === leftTabId);
   const rightTab = eligibleTabs.find((item) => item.id === rightTabId);
@@ -262,6 +264,10 @@ export function AuthorizationTestingWorkspace({
   const sameOrigin = Boolean(leftTab && rightTab && tabOrigin(leftTab) === tabOrigin(rightTab));
   const capabilityReady = bridge.state === 'connected'
     && Boolean(bridge.capabilities?.includes('yakit.browser_authorization.task'));
+  const instanceDiscoveryReady = bridge.state === 'connected'
+    && Boolean(bridge.capabilities?.includes('yakit.browser_authorization.instances'));
+  const currentBrowserInstance = browserInstances.find((instance) => instance.current);
+  const targetBrowserInstance = browserInstances.find((instance) => instance.deviceId === targetDeviceId);
 
   const refreshInspection = useCallback(async () => {
     const next = await request('isolation.inspect', {
@@ -270,6 +276,21 @@ export function AuthorizationTestingWorkspace({
     dispatch({ type: 'patch', value: { inspection: next } });
   }, [eligibleTabs]);
 
+  const refreshBrowserInstances = useCallback(async () => {
+    if (!instanceDiscoveryReady) {
+      setBrowserInstances([]);
+      setTargetDeviceId('');
+      return;
+    }
+    const result = await request('authorization.yakit.instances');
+    setBrowserInstances(result.instances);
+    setTargetDeviceId((current) => (
+      result.instances.some((instance) => !instance.current && instance.deviceId === current)
+        ? current
+        : result.instances.find((instance) => !instance.current)?.deviceId || ''
+    ));
+  }, [instanceDiscoveryReady]);
+
   useEffect(() => {
     void (async () => {
       try {
@@ -315,6 +336,17 @@ export function AuthorizationTestingWorkspace({
     void refreshInspection().catch((error) => setLocalError(errorMessage(error)));
   }, [refreshInspection]);
 
+  useEffect(() => {
+    void refreshBrowserInstances().catch((error) => setLocalError(errorMessage(error)));
+    const refreshWhenVisible = () => {
+      if (document.visibilityState === 'visible') {
+        void refreshBrowserInstances().catch((error) => setLocalError(errorMessage(error)));
+      }
+    };
+    document.addEventListener('visibilitychange', refreshWhenVisible);
+    return () => document.removeEventListener('visibilitychange', refreshWhenVisible);
+  }, [refreshBrowserInstances]);
+
   useEffect(() => {
     if (!hydrated || workspace || !leftTab || !rightTab) return;
     const reason = authorizationIdentityOptionDisabledReason({
@@ -447,11 +479,16 @@ export function AuthorizationTestingWorkspace({
 
   const openCrossBrowserWorkspace = () => run(async () => {
     if (!activeTab) throw new Error('请先选择需要测试的页面');
+    if (!targetBrowserInstance) throw new Error('请选择另一个在线的 YTray 浏览器实例');
     if (!bridge.capabilities?.includes('yakit.browser_authorization.open')) {
       throw new Error('当前 Yak 引擎不支持打开跨浏览器工作区');
     }
-    await request('authorization.yakit.open', { tabId: activeTab.id, mode });
-  }, '已在 Yakit 打开跨浏览器越权测试，并带入当前页面');
+    await request('authorization.yakit.open', {
+      tabId: activeTab.id,
+      mode,
+      targetDeviceId: targetBrowserInstance.deviceId,
+    });
+  }, `已将浏览器 ${currentBrowserInstance?.badge || '当前'} 与 ${targetBrowserInstance?.badge || '对照'} 带入 Yakit`);
 
   const refreshWorkspaceDocuments = async (): Promise<BrowserAuthorizationWorkspace> => {
     if (!workspace || !leftTab || !rightTab) throw new Error('请先建立 A/B 工作区');
@@ -733,15 +770,38 @@ export function AuthorizationTestingWorkspace({
     {!workspace && <section className="authorization-cross-browser">
       <span><UserRoundPlus size={18} /></span>
       <div>
-        <strong>使用 YTray 的多个浏览器实例</strong>
-        <small>把当前页面作为资源身份带入 Yakit，再选择在线的浏览器 A、B 或 C 作为独立对照账号。</small>
+        <strong>选择独立浏览器实例</strong>
+        <small>{!instanceDiscoveryReady
+          ? '当前 Yak 版本不能读取在线实例，请更新引擎后重连。'
+          : browserInstances.length < 2
+            ? '只检测到当前浏览器，请先用 YTray 启动并连接另一个实例。'
+            : '当前页面作为资源所有者，所选浏览器作为独立对照账号。'}</small>
+        <div className="authorization-cross-browser__instances">
+          {browserInstances.map((instance) => <button
+            key={instance.deviceId}
+            type="button"
+            disabled={instance.current}
+            aria-pressed={!instance.current && instance.deviceId === targetDeviceId}
+            className={instance.current ? 'is-current' : instance.deviceId === targetDeviceId ? 'is-selected' : ''}
+            onClick={() => setTargetDeviceId(instance.deviceId)}
+          >
+            <b>{instance.badge}</b>
+            <span>{instance.current ? '当前' : instance.deviceId === targetDeviceId ? '已选择' : '在线'}</span>
+          </button>)}
+          <button
+            type="button"
+            className="is-refresh"
+            aria-label="刷新在线浏览器实例"
+            onClick={() => void refreshBrowserInstances().catch((error) => setLocalError(errorMessage(error)))}
+          ><RefreshCw size={13} /></button>
+        </div>
       </div>
       <Button
         variant="ghost"
-        disabled={busy || !activeTab || !bridge.capabilities?.includes('yakit.browser_authorization.open')}
+        disabled={busy || !activeTab || !targetBrowserInstance || !bridge.capabilities?.includes('yakit.browser_authorization.open')}
         onClick={() => void openCrossBrowserWorkspace()}
       >
-        <ExternalLink size={15} />在 Yakit 选择实例
+        <ExternalLink size={15} />用 {targetBrowserInstance?.badge || '—'} 在 Yakit 测试
       </Button>
     </section>}
 
diff --git a/src/features/authorization-testing/ui/authorization-testing-workspace.css b/src/features/authorization-testing/ui/authorization-testing-workspace.css
index 0eb08aa..c360971 100644
--- a/src/features/authorization-testing/ui/authorization-testing-workspace.css
+++ b/src/features/authorization-testing/ui/authorization-testing-workspace.css
@@ -143,6 +143,10 @@
   display: block;
 }
 
+.authorization-cross-browser > div {
+  min-width: 0;
+}
+
 .authorization-cross-browser strong {
   font-size: var(--text-sm);
 }
@@ -154,6 +158,63 @@
   line-height: 1.45;
 }
 
+.authorization-cross-browser__instances {
+  margin-top: 8px;
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  flex-wrap: wrap;
+}
+
+.authorization-cross-browser__instances > button {
+  height: 27px;
+  padding: 0 8px 0 5px;
+  display: inline-flex;
+  align-items: center;
+  gap: 5px;
+  border: 1px solid var(--border);
+  border-radius: 999px;
+  background: var(--surface);
+  color: var(--muted-strong);
+  font-size: var(--text-xs);
+  cursor: pointer;
+}
+
+.authorization-cross-browser__instances > button > b {
+  width: 18px;
+  height: 18px;
+  display: grid;
+  place-items: center;
+  border-radius: 50%;
+  background: var(--surface-subtle);
+  color: var(--foreground);
+  font-size: var(--text-xs);
+}
+
+.authorization-cross-browser__instances > button.is-current {
+  opacity: 1;
+  background: var(--surface-subtle);
+  color: var(--muted);
+  cursor: default;
+}
+
+.authorization-cross-browser__instances > button.is-selected {
+  border-color: color-mix(in srgb, var(--authorization-accent) 50%, var(--border));
+  background: color-mix(in srgb, var(--authorization-accent) 9%, var(--surface));
+  color: var(--authorization-accent);
+}
+
+.authorization-cross-browser__instances > button.is-selected > b {
+  background: var(--authorization-accent);
+  color: white;
+}
+
+.authorization-cross-browser__instances > button.is-refresh {
+  width: 27px;
+  padding: 0;
+  justify-content: center;
+}
+
 .authorization-identity-stage,
 .authorization-baseline-stage,
 .authorization-plan-stage {
diff --git a/src/protocol/extension.test.ts b/src/protocol/extension.test.ts
index 24a6049..df51e46 100644
--- a/src/protocol/extension.test.ts
+++ b/src/protocol/extension.test.ts
@@ -101,8 +101,10 @@ describe('extension request schemas', () => {
     }).action).toBe('authorization.yakit.open');
     expect(parseExtensionRequest({
       action: 'authorization.yakit.open',
-      payload: { tabId: 12, mode: 'horizontal' },
-    }).payload).toEqual({ tabId: 12, mode: 'horizontal' });
+      payload: { tabId: 12, mode: 'horizontal', targetDeviceId: 'device-b' },
+    }).payload).toEqual({ tabId: 12, mode: 'horizontal', targetDeviceId: 'device-b' });
+    expect(parseExtensionRequest({ action: 'authorization.yakit.instances' }).action)
+      .toBe('authorization.yakit.instances');
     expect(parseExtensionRequest({
       action: 'network.capture.start',
       payload: {
diff --git a/src/protocol/extension.ts b/src/protocol/extension.ts
index b765abf..2ad56ec 100644
--- a/src/protocol/extension.ts
+++ b/src/protocol/extension.ts
@@ -307,8 +307,10 @@ const payloadSchemas = {
     v.strictObject({
       tabId,
       mode: v.optional(v.picklist(['horizontal', 'vertical'])),
+      targetDeviceId: v.optional(id),
     }),
   ]),
+  'authorization.yakit.instances': noPayload,
   'proxy.save': proxyProfile,
   'proxy.delete': v.strictObject({ id }),
   'proxy.switch': v.strictObject({ id }),
diff --git a/src/types/messages.ts b/src/types/messages.ts
index 6ac1053..72ab300 100644
--- a/src/types/messages.ts
+++ b/src/types/messages.ts
@@ -14,6 +14,7 @@ import type {
   BrowserFirefoxManagedContainer,
   BrowserIsolationInspection,
   BrowserIsolationProof,
+  BrowserAuthorizationInstance,
   BrowserDeepCaptureMatcher,
   BrowserDeepCaptureStatus,
   CookieInput,
@@ -97,9 +98,17 @@ export interface ExtensionRequestMap {
     output: unknown;
   };
   'authorization.yakit.open': {
-    input: { workspaceId: string } | { tabId: number; mode?: 'horizontal' | 'vertical' };
+    input: { workspaceId: string } | {
+      tabId: number;
+      mode?: 'horizontal' | 'vertical';
+      targetDeviceId?: string;
+    };
     output: { workspaceId?: string; tabId?: number; opened: boolean };
   };
+  'authorization.yakit.instances': {
+    input: undefined;
+    output: { instances: BrowserAuthorizationInstance[] };
+  };
   'proxy.save': { input: ProxyProfile; output: ExtensionState };
   'proxy.delete': { input: { id: string }; output: ExtensionState };
   'proxy.switch': { input: { id: string }; output: ExtensionState };
diff --git a/src/types/models.ts b/src/types/models.ts
index c3011ce..744e28a 100644
--- a/src/types/models.ts
+++ b/src/types/models.ts
@@ -218,6 +218,12 @@ export interface BridgePairedEngine {
   pairedAt: number;
 }
 
+export interface BrowserAuthorizationInstance {
+  deviceId: string;
+  badge: string;
+  current: boolean;
+}
+
 export type BridgePairingState = 'idle' | 'requesting' | 'pending' | 'approved' | 'rejected' | 'expired' | 'error';
 
 export interface BridgePairingStatus {