The utility model relates to a ponding detection device for a gas conduit. The ponding detection device is characterized by being provided with a gate valve (3), a nipple (4) is mounted on the gate valve (3), a radar detector (5) is mounted on the nipple (4), and the output terminal of the radar detector (5) is connected with a monitor (6). The ponding detection device realizes real-time monitoring of ponding in a gaspipe network, particularly low-lying places, and can promptly and accurately judge the ponding condition in the gaspipe network, thereby ensuring safe running of the gaspipe network system.