The parameter matching of the power system is one of the key steps in the development and research of the extended range hybrid electric bus. The result of the matching will directly determine the power performance, fuel economy and total endurance of the vehicle. In this paper, according to the running characteristics of the bus and the design index of the whole vehicle, the key parameters of the driving motor, power battery, engine and generator in the power system are matched and calculated, and the designed power system is verified. The results show that the design and parameter matching of the vehicle power system are reasonable and meet the preset dynamic and economic requirements of the vehicle.