The invention discloses a vehicle fuel cell stack status monitoring system, comprising a signal processing module, which integrates the functions of single cell voltage patrol inspection, output current monitoring, temperature field monitoring, shock signal monitoring and the like, and can perform data processing, storage, analysis and transmission on the acquired signals. The signal processing module has two power supply modes: external auxiliary power supply and stack power supply. When the stack is normally started, the signal processing module receives power directly from the stack, and the stack performs floating charge on the external auxiliary power supply at the same time; and when the stack stops working or is abnormal, the external auxiliary power supply can be used for auxiliarypower supply. The signal processing module has a dual-port output mode, and can perform data communication with a host computer via a CAN port and data communication with an external PC through a 485port to evaluate the performance of the stack and diagnose the fault.