The utility model provides a power supply system of vehicle and have its vehicle, wherein, the system includes: fuel cell power supply unit, fuel cell power supply unit include fuel cell and fuel cell voltage converting apparatus, fuel cell voltage converting apparatus links to each other with high -pressure generating line and fuel cell respectively, control switch, control switch sets up on high -pressure generating line to control the break -make of high -pressure generating line, a plurality of electrical parts for the vehicle, a plurality of for the vehicle electrical part and high -pressure generating line link to each other, a plurality of for the vehicle electrical part parallelly connected, a plurality of for the vehicle electrical part obtain the electric energy by high -pressure generating line. This power supply system can supply power for electrical part for the vehicle through fuel cell, and is not only energy -concerving and environment -protective, has improved the continuation of the journey mileage of vehicle in addition, guarantees the reliability of vehicle better, simple easy the realization.