diff --git a/src/ppclock/cli.py b/src/ppclock/cli.py
index 3d4d3fb..548b0c7 100644
--- a/src/ppclock/cli.py
+++ b/src/ppclock/cli.py
@@ -248,26 +248,31 @@ async def _run_command(args, t):
             await t.write_rxtx(data, response=not args.no_response)
         return {"sent": len(data)}
     if c == "ota":
-        import zlib
         from pathlib import Path
         image = Path(args.file).read_bytes()
-        # 独立预检（pQ 头 + CRC32(body)），与 tools/fw.py 同规则
-        if len(image) < 64 or image[0:2] != b"pQ":
-            raise ValueError("固件格式错误（缺 pQ 头）")
-        body_size = int.from_bytes(image[4:8], "little")
-        crc_ok = (zlib.crc32(image[64:64 + body_size]) & 0xFFFFFFFF
-                  == int.from_bytes(image[8:12], "little"))
-        if not crc_ok:
-            raise ValueError("固件 CRC 校验失败，拒绝烧录")
-        if not args.yes:
-            return {"precheck": "ok", "body_size": body_size,
-                    "hint": "加 --yes 执行烧录"}
+        _ota_precheck(args)  # 不合格直接抛 ValueError
         progress_log = []
         result = await t.run_ota(image, on_progress=progress_log.append)
         return {"ota": "done", **result, "blocks_ok": len(progress_log)}
     raise ValueError(f"未知命令 {c}")
 
 
+def _ota_precheck(args) -> dict:
+    """无设备场景的固件预检（--yes 才需要连接）。"""
+    import zlib
+    from pathlib import Path
+    image = Path(args.file).read_bytes()
+    if len(image) < 64 or image[0:2] != b"pQ":
+        raise ValueError("固件格式错误（缺 pQ 头）")
+    body_size = int.from_bytes(image[4:8], "little")
+    crc_ok = (zlib.crc32(image[64:64 + body_size]) & 0xFFFFFFFF
+              == int.from_bytes(image[8:12], "little"))
+    if not crc_ok:
+        raise ValueError("固件 CRC 校验失败，拒绝烧录")
+    return {"precheck": "ok", "body_size": body_size,
+            "hint": "加 --yes 执行烧录"}
+
+
 async def _run_batch(args) -> list:
     lines = (sys.stdin.read() if args.file == "-"
              else open(args.file, encoding="utf-8").read())
@@ -298,6 +303,8 @@ async def _dispatch(args) -> dict | list | None:
         return {"devices": await scan(timeout=args.timeout)}
     if args.cmd == "batch":
         return {"results": await _run_batch(args)}
+    if args.cmd == "ota" and not args.yes:
+        return _ota_precheck(args)  # 预检无需设备
     return await _run_with_transport(args, lambda t: _run_command(args, t))