The invention provides a vehicle fuel cell system and method for low temperature starting through an alloy hydrogen storage material. The vehicle fuel cell system comprises a fuel cell stack, an air path subsystem, a hydrogen path subsystem, a cooling liquid path subsystem and a control circuit subsystem, the hydrogen path subsystem comprises an alloy hydrogen storage tank branch path and a high pressure gas bottle branch path, and an alloy hydrogen storage tank is arranged in a water box of the cooling liquid path subsystem. The method for low temperature starting comprises the steps of making a high pressure gas bottle inflate an alloy hydrogen storage tank with hydrogen, when the hydrogen storage material is inflated with hydrogen, conducting heat release, heating cooling liquid in thewater box, when the cooling liquid reaches set temperature, starting a circulation water pump, heating a fuel cell electric stack, when the electric stack reaches set operable temperature, stopping hydrogen inflation and starting the fuel cell system. The vehicle fuel cell system and method have the advantages that fuel is not consumed, and external heating equipment is not added, so that high pressure gas bottle hydrogen storage and hydrogen storage material hydrogen storage supplement each other; when low temperature starting is not needed, the driving mileage of a fuel cell vehicle can alsobe increased.