The invention provides a fuel cell vehicle which comprises a compartment, wherein a fuel bin which transversely passes through the compartment is arranged at the bottom of the compartment, fuel tanksare arranged in the fuel bin, a wheeled running device is arranged at the bottom of each fuel tank, and the wheeled running device is used for driving each fuel tank to automatically move out of or move into the fuel bin. When the fuel cell vehicle passes through a ventilation channel at a specified vehicle speed, an empty fuel tank moves onto a first conveying belt on a ventilation platform at one side from the fuel bin, simultaneously, a full fuel tank moves into the fuel bin from a second conveying belt on a ventilation platform at the other side, and the speed of the first conveying belt and the speed of the second conveying belt are synchronized with the specified vehicle speed. The fuel cell vehicle provided by the invention has the advantages that because the wheeled running deviceis arranged at the bottom of each fuel tank and the first conveying belt and the second conveying belt of which the speeds are synchronized with the specified vehicle speed are arranged on the ventilation platform, the fuel tank can move out of or move into the fuel bin through the first conveying belt and the second conveying belt, and the process of replacing the fuel tank by parking is not needed. The invention also provides a fuel supplementing method of the fuel cell vehicle.