diff --git a/agv_app/app.py b/agv_app/app.py
index 42a21da..d567c60 100644
--- a/agv_app/app.py
+++ b/agv_app/app.py
@@ -1130,26 +1130,16 @@ def api_camera_capture():
 
 @app.route("/api/camera/arm_refresh")
 def api_arm_camera_refresh():
-    """从机械臂拉一张 JPEG（流式读第一个完整帧）"""
+    """从机械臂拉一张 JPEG（请求 snapshot 端点，简单 HTTP GET）"""
     import requests
     try:
-        r = requests.get(ARM_CAMERA_CONFIG["url"], stream=True, timeout=8)
-        if r.status_code != 200:
-            return "", 404
-        data = b""
-        for chunk in r.iter_content(chunk_size=8192):
-            data += chunk
-            # 在累积数据中找 JPEG 完整帧
-            s = data.find(b"\xff\xd8")
-            e = data.find(b"\xff\xd9", s + 2) if s >= 0 else -1
-            if s >= 0 and e > s:
-                r.close()
-                return Response(data[s:e+2], mimetype="image/jpeg")
-            # 累积超过 5MB 还没找到完整帧，说明流异常，放弃
-            if len(data) > 5 * 1024 * 1024:
-                r.close()
-                return "", 404
-        r.close()
+        r = requests.get(ARM_CAMERA_CONFIG.get("snapshot_url", ARM_CAMERA_CONFIG["url"]), timeout=8)
+        if r.status_code == 200 and r.content:
+            resp = Response(r.content, mimetype="image/jpeg")
+            resp.headers["Cache-Control"] = "no-cache, no-store, must-revalidate, max-age=0"
+            resp.headers["Pragma"] = "no-cache"
+            resp.headers["Expires"] = "0"
+            return resp
         return "", 404
     except Exception as ex:
         logger.error(f"arm_refresh 失败: {ex}")
diff --git a/agv_app/config.py b/agv_app/config.py
index 1d1349d..21abed5 100644
--- a/agv_app/config.py
+++ b/agv_app/config.py
@@ -40,6 +40,7 @@ CAMERA_CONFIG = {
 # ========== 机械臂摄像头流 ==========
 ARM_CAMERA_CONFIG = {
     "url": "http://192.168.110.164:5003/api/camera/preview",
+    "snapshot_url": "http://192.168.110.164:5003/api/camera/snapshot",
 }
 
 # ========== HTTP 上传 ==========
diff --git a/arm_server/arm_server.py b/arm_server/arm_server.py
index 1723b46..b389e08 100644
--- a/arm_server/arm_server.py
+++ b/arm_server/arm_server.py
@@ -45,6 +45,7 @@ def _ensure_ffmpeg():
                 "ffmpeg",
                 "-f", "v4l2",
                 "-input_format", "mjpeg",
+                "-re",
                 "-i", f"/dev/video{ARM_CAMERA_INDEX}",
                 "-vf", "rotate=PI",
                 "-q:v", "8",
@@ -103,6 +104,40 @@ def arm_camera_restart():
     _ensure_ffmpeg()
     return jsonify({"ok": True})
 
+@arm_video_app.route("/api/camera/snapshot")
+def arm_camera_snapshot():
+    """机械臂摄像头单帧 JPEG — pkill -9 强杀旧 ffmpeg，再临时抓一帧"""
+    import subprocess
+    global _ffmpeg_proc
+    # 用 pkill -9 强杀所有 ffmpeg 进程，释放 /dev/video0
+    subprocess.run(["pkill", "-9", "-f", "ffmpeg"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, timeout=3)
+    time.sleep(0.3)
+    _ffmpeg_proc = None
+    proc = subprocess.run(
+        [
+            "ffmpeg",
+            "-f", "v4l2",
+            "-input_format", "mjpeg",
+            "-i", f"/dev/video{ARM_CAMERA_INDEX}",
+            "-vf", "rotate=PI",
+            "-vframes", "1",
+            "-q:v", "8",
+            "-f", "mjpeg",
+            "pipe:1"
+        ],
+        stdout=subprocess.PIPE,
+        timeout=5,
+        stderr=subprocess.DEVNULL
+    )
+    if proc.returncode == 0 and proc.stdout:
+        r = Response(proc.stdout, mimetype="image/jpeg")
+        r.headers["Cache-Control"] = "no-cache, no-store, must-revalidate, max-age=0"
+        r.headers["Pragma"] = "no-cache"
+        r.headers["Expires"] = "0"
+        return r
+    logger.warning(f"ffmpeg snapshot failed: rc={proc.returncode}")
+    return "", 500
+
 
 # ========== RoboFlow 630 Socket API 客户端 ==========
 class RoboFlowClient: