diff --git a/backend/app/ai_tools.py b/backend/app/ai_tools.py
index 936be33..5edbe36 100644
--- a/backend/app/ai_tools.py
+++ b/backend/app/ai_tools.py
@@ -14,34 +14,34 @@ log = logging.getLogger("dpm.ai_tools")
 
 # ---------------- 工具执行 ----------------
 
-def execute_tool(tool):
-    """执行一个工具调用：发布 MQTT 控制指令，返回是否发布成功"""
+def execute_tool(tool, screen_id=""):
+    """执行一个工具调用：发布 MQTT 控制指令（带发起屏幕 screen_id，只发到该屏），返回是否发布成功"""
     t = tool.get("type")
     params = tool.get("params") or {}
     if t == "navigate":
-        return hub.publish_command("navigate", {"page": params.get("page", "home")}).get("published", False)
+        return hub.publish_command("navigate", {"page": params.get("page", "home")}, screen_id=screen_id).get("published", False)
     if t == "control":
         action = params.get("action")
         if action in ("play", "pause", "next", "prev"):
-            return hub.publish_command(action).get("published", False)
+            return hub.publish_command(action, screen_id=screen_id).get("published", False)
         if action == "set_mode":
-            return hub.publish_command("set_mode", {"mode": params.get("mode", "auto")}).get("published", False)
+            return hub.publish_command("set_mode", {"mode": params.get("mode", "auto")}, screen_id=screen_id).get("published", False)
         return False
     if t == "alert":
-        return hub.publish_command("alert", {"title": params.get("title", "提示"), "content": params.get("content", "")}).get("published", False)
+        return hub.publish_command("alert", {"title": params.get("title", "提示"), "content": params.get("content", "")}, screen_id=screen_id).get("published", False)
     if t == "show_card":
-        return hub.publish_command("show_card", params).get("published", False)
+        return hub.publish_command("show_card", params, screen_id=screen_id).get("published", False)
     return False
 
 
-def run_tools(tools):
-    """执行一组工具，返回 [{type, ok}] 并汇总是否全部发布成功"""
+def run_tools(tools, screen_id=""):
+    """执行一组工具（带发起屏幕 screen_id），返回 [{type, ok}] 并汇总是否全部发布成功"""
     results = []
     all_ok = True
     for tool in tools or []:
-        ok = bool(execute_tool(tool))
-        log.info("ai_tools: 执行工具 %s params=%s -> %s", tool.get("type"),
-                 json.dumps(tool.get("params") or {}, ensure_ascii=False), ok)
+        ok = bool(execute_tool(tool, screen_id))
+        log.info("ai_tools: 执行工具 %s params=%s screen=%s -> %s", tool.get("type"),
+                 json.dumps(tool.get("params") or {}, ensure_ascii=False), screen_id or "all", ok)
         results.append({"type": tool.get("type"), "ok": ok})
         all_ok = all_ok and ok
     return results, all_ok
diff --git a/backend/app/llm.py b/backend/app/llm.py
index a275c0c..08829d6 100644
--- a/backend/app/llm.py
+++ b/backend/app/llm.py
@@ -135,32 +135,32 @@ def _chat_once(messages, with_tools=True):
         return json.loads(resp.read().decode("utf-8"))
 
 
-def _fallback(messages):
+def _fallback(messages, screen_id=""):
     """DashScope 不可用时回退本地规则引擎"""
     from .ai_tools import run_chat as rule_run
 
     result = rule_run(messages)
-    # 规则引擎产出的工具同样执行（MQTT 广播），并汇总发布结果
-    _, all_ok = _exec_all(result.get("tools", []))
+    # 规则引擎产出的工具同样执行（MQTT 广播，带发起屏幕），并汇总发布结果
+    _, all_ok = _exec_all(result.get("tools", []), screen_id)
     result["model"] = "rule-engine"
     result["mqtt_published"] = all_ok
     return result
 
 
-def _exec_all(tools):
-    """执行工具列表，返回 (results, all_ok)"""
+def _exec_all(tools, screen_id=""):
+    """执行工具列表（带发起屏幕 screen_id，工具结果只发到该屏），返回 (results, all_ok)"""
     from .ai_tools import run_tools
 
-    results, all_ok = run_tools(tools)
+    results, all_ok = run_tools(tools, screen_id)
     return results, all_ok
 
 
-def run_chat(messages):
+def run_chat(messages, screen_id=""):
     """入口：{reply, tools, model}
-       tools 已在后端执行（MQTT 广播），返回值供请求端本地同步执行"""
+       tools 已在后端执行（MQTT 广播，带发起屏幕 screen_id），返回值供请求端本地同步执行"""
     if not settings.DASHSCOPE_API_KEY:
         log.warning("未配置 DASHSCOPE_API_KEY，使用本地规则引擎")
-        return _fallback(messages)
+        return _fallback(messages, screen_id)
 
     # 注入园区知识库（标准资料口径）：按用户 query 检索命中段落动态注入，
     # 替代原 1200 字截断全量注入（避免尾部知识丢失）。无命中时回退 brief()。
@@ -226,7 +226,7 @@ def run_chat(messages):
                     "content": json.dumps({"ok": True}, ensure_ascii=False),
                 })
             # 工具执行（MQTT 广播），并汇总发布结果
-            results, all_ok = _exec_all(executed)
+            results, all_ok = _exec_all(executed, screen_id)
             log.info("llm: 工具执行结果 %s", results)
             for t in executed:
                 log.info("llm:   执行 %s %s", t["type"], json.dumps(t["params"], ensure_ascii=False))
diff --git a/backend/app/routers.py b/backend/app/routers.py
index 86c434c..b65c963 100644
--- a/backend/app/routers.py
+++ b/backend/app/routers.py
@@ -84,6 +84,7 @@ class ChatMessage(BaseModel):
 
 class ChatBody(BaseModel):
     messages: list[ChatMessage]
+    screen_id: str = ""   # 发起对话的屏幕设备 id（工具结果只发到该屏）
 
 
 # ==================== 认证 / 设置 ====================
@@ -451,7 +452,7 @@ async def ai_chat(body: ChatBody):
     """大模型对话：工具调用（切页/控制/卡片/通知）经 MQTT 广播到所有大屏
        返回 {reply, tools, model}；tools 供请求端本地同步执行"""
     messages = [m.model_dump() for m in body.messages]
-    result = llm_run_chat(messages)
+    result = llm_run_chat(messages, body.screen_id or "")
     return result
 
 
@@ -604,6 +605,7 @@ def vision_llm(body: VisionLlmBody):
 class ToolsExecBody(BaseModel):
     name: str = ""
     args: dict = {}
+    screen_id: str = ""   # 发起语音对话的屏幕设备 id（工具结果只发到该屏）
 
 @router.post("/api/tools/exec")
 def tools_exec(body: ToolsExecBody):
@@ -612,10 +614,10 @@ def tools_exec(body: ToolsExecBody):
     if not name:
         return {"ok": False, "error": "missing tool name"}
     from .tools import exec_tool
-    result = exec_tool(name, body.args or {})
-    log.info("api: /api/tools/exec name=%s args=%s result=%s", name,
+    result = exec_tool(name, body.args or {}, body.screen_id or "")
+    log.info("api: /api/tools/exec name=%s args=%s screen=%s result=%s", name,
              json.dumps(body.args or {}, ensure_ascii=False)[:300],
-             str(result)[:400])
+             body.screen_id or "all", str(result)[:400])
     return {"ok": True, "result": result}
 
 @router.get("/api/kb/brief")
diff --git a/backend/app/tools.py b/backend/app/tools.py
index e7bf81e..e0562d2 100644
--- a/backend/app/tools.py
+++ b/backend/app/tools.py
@@ -60,15 +60,15 @@ def _query_companies(args):
     }, ensure_ascii=False)
 
 
-def _control_display(args):
-    """大屏显示控制：切页 / 弹通知 / 媒体播放暂停（经 MQTT 广播到大屏）"""
+def _control_display(args, screen_id=""):
+    """大屏显示控制：切页 / 弹通知 / 媒体播放暂停（经 MQTT 按发起屏幕下发）"""
     from .mqtt import hub
     action = (args.get("action") or "").strip()
     target = (args.get("target") or "").strip()
     if action not in ("switch_page", "alert", "media_play", "media_pause"):
         return json.dumps({"error": f"不支持的 action: {action}"}, ensure_ascii=False)
     params = {"target": target} if target else {}
-    ok = hub.publish_command(action, params).get("published", False)
+    ok = hub.publish_command(action, params, screen_id=screen_id).get("published", False)
     return json.dumps({"ok": ok, "action": action, "target": target}, ensure_ascii=False)
 
 
@@ -125,15 +125,19 @@ def tool_schemas():
     ]
 
 
-def exec_tool(name: str, args: dict):
-    """执行工具 → 返回给 LLM 的字符串结果（JSON）"""
+def exec_tool(name: str, args: dict, screen_id: str = ""):
+    """执行工具 → 返回给 LLM 的字符串结果（JSON）。
+       控制类工具（control_display）按发起屏幕 screen_id 只下发到该屏。"""
     t = TOOLS.get(name)
     if not t:
         log.warning("tools: 未知工具 %s", name)
         return json.dumps({"error": f"未知工具: {name}"}, ensure_ascii=False)
     try:
-        result = t["fn"](args or {})
-        log.info("tools: 执行工具 %s args=%s", name, json.dumps(args, ensure_ascii=False))
+        if name == "control_display":
+            result = _control_display(args or {}, screen_id)
+        else:
+            result = t["fn"](args or {})
+        log.info("tools: 执行工具 %s args=%s screen=%s", name, json.dumps(args, ensure_ascii=False), screen_id or "all")
         log.info("tools:   结果 -> %s", _trunc(result, 1000))
         return result
     except Exception as e:  # noqa: BLE001
diff --git a/backend/static/admin.js b/backend/static/admin.js
index 175bb8b..5bd9e9f 100644
--- a/backend/static/admin.js
+++ b/backend/static/admin.js
@@ -193,7 +193,7 @@
     if (btn.id === 'mqttAiSend') {
       var text = (document.getElementById('mqttAiInput').value || '').trim();
       if (!text) { toast('请输入问题', 'error'); return; }
-      post('/api/display/command', { action: 'ai_input', params: { text: text } }, function () {
+      post('/api/display/command', { action: 'ai_input', params: { text: text }, screen_id: screenId, screen_role: screenRole }, function () {
         toast('已发送问题到大屏 AI 页');
       });
       return;
@@ -203,17 +203,20 @@
     if (btn.id === 'mqttAlertSend') {
       var alertText = (document.getElementById('mqttAlertText').value || '').trim();
       if (!alertText) { toast('请输入通知内容', 'error'); return; }
-      post('/api/display/command', { action: 'alert', params: { text: alertText } }, function () {
-        toast('通知已广播');
+      post('/api/display/command', { action: 'alert', params: { text: alertText }, screen_id: screenId, screen_role: screenRole }, function () {
+        toast('通知已发送');
       });
       return;
     }
 
-    // 页面切换
+    // 页面切换（绑定目标屏幕：screen_id 精确某台；空=全部）
     if (btn.hasAttribute('data-nav')) {
       var page = btn.getAttribute('data-nav');
-      post('/api/display/command', { action: 'navigate', params: { page: page } }, function () {
-        toast('已切换大屏至「' + btn.textContent.trim() + '」');
+      var tgtTxt = screenId
+        ? (screenRole === 'main' ? '主屏' : screenRole === 'secondary' ? '副屏' : '屏幕') + '·' + String(screenId).slice(0, 10)
+        : '全部';
+      post('/api/display/command', { action: 'navigate', params: { page: page }, screen_id: screenId, screen_role: screenRole }, function () {
+        toast('已切换大屏至「' + btn.textContent.trim() + '」 → ' + tgtTxt);
       });
       return;
     }
diff --git a/src/components/AiChatPanel.jsx b/src/components/AiChatPanel.jsx
index cc8b137..21105b3 100644
--- a/src/components/AiChatPanel.jsx
+++ b/src/components/AiChatPanel.jsx
@@ -3,7 +3,7 @@ import Icon from './Icons';
 import ShowCard from './ShowCard';
 import { getApiBase as API_BASE } from '../config';
 import { Sfx } from '../utils/sounds';
-import { getMqttStatus } from '../utils/mqtt';
+import { getMqttStatus, getClientId } from '../utils/mqtt';
 import { aiStatus } from '../utils/statusBus';
 import { renderMarkdown } from '../voice/markdown.jsx';
 
@@ -161,7 +161,7 @@ export default function AiChatPanel() {
       const res = await fetch(`${API_BASE()}/api/ai/chat`, {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ messages: history }),
+        body: JSON.stringify({ messages: history, screen_id: getClientId() }),
       });
       if (res.ok) {
         data = await res.json();
diff --git a/src/pages/VoiceAssistant.jsx b/src/pages/VoiceAssistant.jsx
index 17c85a2..a28aea8 100644
--- a/src/pages/VoiceAssistant.jsx
+++ b/src/pages/VoiceAssistant.jsx
@@ -9,6 +9,7 @@ import { useCallback, useEffect, useRef, useState } from 'react';
 import { S2sWsRealtimeClient } from '../voice/s2s-ws-client.js';
 import useVisionDetection, { VISION_DWELL_MS } from '../voice/useVisionDetection.js';
 import { getApiBase as API_BASE, getVoiceWsUrl } from '../config';
+import { getClientId } from '../utils/mqtt';
 import { aiStatus } from '../utils/statusBus';
 import '../styles/datascreen.css';
 import './voice-original.css';
@@ -242,7 +243,7 @@ export default function VoiceAssistant() {
       const res = await fetch(`${API_BASE()}/api/tools/exec`, {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ name, args }),
+        body: JSON.stringify({ name, args, screen_id: getClientId() }),
       });
       const data = await res.json();
       output = data?.result ?? JSON.stringify(data);