Abstract: The power matching of the electric motor, battery and transmission ratio is designed according to the vehicle parameters and the vehicle performance indicators. The vehicle simulation model, the electric motor and the battery model were built for analyzing the power performance and the economy performance based on the Cruise simulation software. Results show that the maximum velocity, the acceleration time of the 0-75m and the 0-80km/h, and the driving range act well with the design specification. Lastly, real vehicle test about the power performance and the economy performance were carried out on the car and the results were basically consistent with the simulation results. This further demonstrated the validity of the power system design based on Cruise simulation software.