diff --git a/apps/mosquito/mqtt_task.py b/apps/mosquito/mqtt_task.py
index ae7fefb..a7aef0b 100644
--- a/apps/mosquito/mqtt_task.py
+++ b/apps/mosquito/mqtt_task.py
@@ -60,9 +60,12 @@ def on_message(client, userdata, message):
 
 def update_device_info(device_id: str, post_data: Dict):
     device = DeviceInfo.objects.filter(device_id=device_id).first()
-    latitude, longitude = post_data['positioning'].split(',')
-    latitude = float(latitude.replace('N ', ''))
-    longitude = float(longitude.replace('E ', ''))
+    if post_data['positioning']:
+        latitude, longitude = post_data['positioning'].split(',')
+        latitude = float(latitude.replace('N ', ''))
+        longitude = float(longitude.replace('E ', ''))
+    else:
+        latitude, longitude = None, None
 
     count = post_data['count']
     signal = post_data['signal']