A fault diagnosis method includes establishing a wireless connection with a home gateway device in a local area network, if the wireless connection is successfully established, sending a diagnosis request to the home gateway device such that the home gateway device performs fault diagnosis, and receiving a fault diagnosis result returned by the home gateway device. After successfully establishing a wireless connection with a home gateway device in a local area network, a terminal sends a diagnosis request to the home gateway device to trigger the home gateway device to perform fault diagnosis.