This power supply system of a fuel cell vehicle is provided with a load, a fuel cell, a power storage device, a first DC-DC converter, a second DC-DC converter, a current-measuring device, a voltage-measuring device, and a controller. The controller performs a feedback control of the first DC-DC converter such that input current or output current measured by the current-measuring device becomes a target current, and also performs a feedback control of the second DC-DC converter such that input voltage or output voltage measured by the voltage-measuring device becomes a target voltage.