On-board test method, device and test system for watchdog chip

The invention discloses an on-board testing method, device and system for a watchdog chip. The method comprises the following steps: in response to a power-on starting signal, triggering an in-board application program to normally generate a dog feeding signal, and sending a first waveform signal to a test module through a first port to identify that a watchdog chip is in a normal zero clearing state; when a test starting signal sent by the test module is received through the second port, the application program is triggered to stop sending a dog feeding signal, and a second waveform signal is synchronously sent to the test module through the first port; and after the tested single board is successfully reset through the watchdog chip, the first waveform signal is sent to the test module again through the first port. According to the technical scheme provided by the embodiment of the invention, the test device is utilized to trigger the program instruction on the tested single board, so that the conditions of