diff --git a/src/mqtt_client_wrapper.cpp b/src/mqtt_client_wrapper.cpp
index d7e12d4..167a3fd 100644
--- a/src/mqtt_client_wrapper.cpp
+++ b/src/mqtt_client_wrapper.cpp
@@ -30,6 +30,24 @@ static void on_mqtt_message_received(const std::string &topic, const std::string
     {
         if (topic == g_app_config.mqtt.topics.video_down)
         {
+            LOG_INFO("[MQTT] Step 1: parsing json");
+            auto j = nlohmann::json::parse(message);
+
+            LOG_INFO("[MQTT] Step 2: checking data field");
+            if (!j.contains("data"))
+            {
+                LOG_WARN("[MQTT] missing data");
+                return;
+            }
+            if (!j["data"].contains("status"))
+            {
+                LOG_WARN("[MQTT] missing status");
+                return;
+            }
+
+            int status = j["data"]["status"].get<int>();
+            LOG_INFO("[MQTT] Step 3: got status=" + std::to_string(status));
+
             // 处理 video_down
             auto j = nlohmann::json::parse(message);