diff --git a/mcp_server/mcp_server.py b/mcp_server/mcp_server.py
index 11ffb38..1fe77e5 100644
--- a/mcp_server/mcp_server.py
+++ b/mcp_server/mcp_server.py
@@ -18,6 +18,11 @@ logging.basicConfig(level=logging.INFO,
 _log = logging.getLogger("mcp")
 
 S = config.Settings()
+
+# 坐标空间缓存：serial -> (display_w, display_h, native_w, native_h)
+# de_screenshot 返回的图与 de_tap/de_swipe 的坐标同一空间（display），
+# server 按比例换算为设备原生坐标（模型只感知截图坐标系，不感知原生分辨率）。
+_coord = {}
 audit.init(S.audit_file)
 
 mcp = FastMCP("mobile-control")
@@ -47,6 +52,16 @@ def _check_write():
         raise PlatformError("write_disabled", "写操作未启用（MCP_ALLOW_WRITE=1 开启）")
 
 
+def _to_native(serial, x, y):
+    """截图坐标 → 设备原生坐标（按最近一次截图的比例换算）。"""
+    c = _coord.get(serial)
+    if not c:
+        raise PlatformError("invalid_param",
+                            "请先对该设备执行 de_screenshot（需要建立坐标空间）")
+    dw, dh, nw, nh = c
+    return (round(x * nw / dw), round(y * nh / dh))
+
+
 def _err(e: PlatformError):
     return {"ok": False, "error": {"code": e.code, "message": e.message}}
 
@@ -96,40 +111,52 @@ def de_screenshot(serial: str) -> dict:
         buf = io.BytesIO()
         img.convert("RGB").save(buf, "JPEG", quality=S.jpeg_quality)
         data = base64.b64encode(buf.getvalue()).decode()
+        # 记录坐标空间（display=返回图尺寸，native=设备原生），供 tap/swipe 换算
+        nw, nh = platform().screen_size(serial)
+        _coord[serial] = (img.size[0], img.size[1], nw, nh)
     except PlatformError as e:
         return _err(e)
     except Exception as e:
         return _err(PlatformError("platform_unavailable", f"截图处理失败: {e}"))
     audit.audit("de_screenshot", serial, f"{w}x{h}", "ok")
+    dw, dh, nw, nh = _coord[serial]
     return _ok({"image": {"type": "image", "data": data,
                           "mimeType": "image/jpeg"},
-                "width": w, "height": h,
+                "width": dw, "height": dh,
+                "native_size": {"width": nw, "height": nh},
                 "screen_state": screen_state})
 
 
 @mcp.tool()
 def de_tap(serial: str, x: int, y: int) -> dict:
-    """点击设备屏幕指定坐标（设备原生分辨率像素，与截图 1:1 换算）。"""
+    """点击设备屏幕指定坐标。
+
+    坐标空间 = de_screenshot 返回的图像坐标（display 空间）——先截图拿到
+    native_size 后再点击，server 自动换算为设备原生坐标。
+    """
     try:
         _check_write()
         serial = _check_serial(serial)
         if x < 0 or y < 0:
             raise PlatformError("invalid_param", "坐标不能为负")
-        platform().tap(serial, x, y)
+        nx, ny = _to_native(serial, x, y)
+        platform().tap(serial, nx, ny)
     except PlatformError as e:
         return _err(e)
-    audit.audit("de_tap", serial, f"({x},{y})", "ok")
+    audit.audit("de_tap", serial, f"({x},{y})->native({nx},{ny})", "ok")
     return _ok({"action": "tap", "serial": serial, "x": x, "y": y})
 
 
 @mcp.tool()
 def de_swipe(serial: str, x1: int, y1: int, x2: int, y2: int,
              duration: float = 0.2) -> dict:
-    """在设备屏幕上滑动（起终点为原生分辨率像素）。"""
+    """在设备屏幕上滑动（坐标空间同 de_tap：截图坐标，server 换算原生）。"""
     try:
         _check_write()
         serial = _check_serial(serial)
-        platform().swipe(serial, x1, y1, x2, y2, duration)
+        nx1, ny1 = _to_native(serial, x1, y1)
+        nx2, ny2 = _to_native(serial, x2, y2)
+        platform().swipe(serial, nx1, ny1, nx2, ny2, duration)
     except PlatformError as e:
         return _err(e)
     audit.audit("de_swipe", serial, f"({x1},{y1})->({x2},{y2})", "ok")
diff --git a/mcp_server/platform_client.py b/mcp_server/platform_client.py
index 3cf4f0d..ff3fb9f 100644
--- a/mcp_server/platform_client.py
+++ b/mcp_server/platform_client.py
@@ -80,6 +80,19 @@ class PlatformClient:
                                 f"截图 HTTP {r.status_code}")
         return r.content, r.headers.get("X-Screen-State", "unknown")
 
+    def screen_size(self, serial):
+        """屏幕原生分辨率（GET /api/screen/size），返回 (w, h)。"""
+        r = self._get("/api/screen/size", serial=serial)
+        if r.status_code == 503:
+            raise PlatformError("device_offline", r.text[:120])
+        if r.status_code != 200:
+            raise PlatformError("platform_unavailable",
+                                f"分辨率 HTTP {r.status_code}")
+        j = r.json() or {}
+        if not j.get("ok"):
+            raise PlatformError("device_offline", str(j.get("error", "取分辨率失败"))[:120])
+        return int(j["width"]), int(j["height"])
+
     def tap(self, serial, x, y):
         """点击（POST /api/screen/tap）。"""
         r = self._post("/api/screen/tap", json={"serial": serial,