The invention relates to a fuel cell vehicle heat balance test device and test method. According to the test device, a vehicle control unit CAN bus, an analyzer, a current sensor, a voltage sensor, atemperature sensor, a pressure sensor, a flow sensor, a wind speed sensor and a data acquisition module are adopted to synchronously acquire key signals of current, voltage, temperature, pressure, flow, wind speed and the like of key components such as a vehicle passenger compartment, an electric pile, a cooling water pump, a radiator, a heater, a battery, a motor, a controller and the like, and can also acquire signals of an environment bin and a chassis dynamometer; and therefore, signal acquisition is comprehensive and reliable. The fuel cell vehicle heat balance test device and test methodcan be used for high-temperature heat balance test and research and development verification of fuel cell vehicles. According to the test device, CAN data are adopted, so that the problem that some thermal management test key signals of a vehicle are difficult to obtain can be effectively solved.