diff --git a/feature_bridge/src/main/ets/core/MessageCodec.ets b/feature_bridge/src/main/ets/core/MessageCodec.ets
index 7028204..78413bf 100644
--- a/feature_bridge/src/main/ets/core/MessageCodec.ets
+++ b/feature_bridge/src/main/ets/core/MessageCodec.ets
@@ -48,12 +48,33 @@ export class MessageCodec {
     for (const o of arr) {
       const m = new Message();
       m.handlerName = o.handlerName;
-      m.data = o.data;
+      // data/responseData：H5 可能直接传对象（如 SwitchOverGameData）。Android org.json
+      // getString 会把嵌套对象强制转成 JSON 字符串，handler 再 JSON.parse；这里复刻该语义，
+      // 否则对象原样传到 handler 后 JSON.parse(对象) 会得到 "[object Object]" 而解析失败。
+      m.data = MessageCodec.coerceToString(o.data);
       m.callbackId = o.callbackId;
       m.responseId = o.responseId;
-      m.responseData = o.responseData;
+      m.responseData = MessageCodec.coerceToString(o.responseData);
       list.push(m);
     }
     return list;
   }
+
+  /**
+   * 复刻 Android org.json `getString` 对 data/responseData 的取值语义：
+   * 字符串原样返回；对象/数组转紧凑 JSON 字符串；数字/布尔转其字符串；null/缺省返回 undefined。
+   */
+  private static coerceToString(v: Object | undefined): string | undefined {
+    if (v === undefined || v === null) {
+      return undefined;
+    }
+    const t: string = typeof v;
+    if (t === 'string') {
+      return v as string;
+    }
+    if (t === 'object') {
+      return JSON.stringify(v);
+    }
+    return String(v);
+  }
 }
diff --git a/feature_capabilities/src/main/ets/providers/NavProvider.ets b/feature_capabilities/src/main/ets/providers/NavProvider.ets
index 66f660c..f48a480 100644
--- a/feature_capabilities/src/main/ets/providers/NavProvider.ets
+++ b/feature_capabilities/src/main/ets/providers/NavProvider.ets
@@ -60,7 +60,9 @@ export class NavProvider implements CapabilityProvider {
       this.log.w(`SwitchOverGameData bad json: ${(e as Error).message}`);
       return;
     }
-    const payload: SwitchGamePayload = { webtype: req.webtype, dir: req.Gamedirectory, data: req.data };
+    // webtype 契约为 "2"竖/"3"横，但 H5 可能发数字（如 3）。统一转字符串，
+    // 否则下游 `webtype !== '2'` 的严格比较对数字恒为真，会把竖屏子游戏错误强制横屏。
+    const payload: SwitchGamePayload = { webtype: String(req.webtype), dir: req.Gamedirectory, data: req.data };
     EventBus.emit(NavEvents.SWITCH_GAME, payload);
   }