In this paper, based on the existing basic parameters of Ev, Combining the corresponding performance index requirements and the driving process of the vehicle power and economic requirements，using the knowledge of vehicle theory, the power performance parameters of ev are designed and matched. After the parameters needed for modeling are obtained, the power simulation model of EV is established by using the Simulink module of MATLAB software, and its rationality is verified. In order to improve the universality of the model and achieve better visual visibility, data calculation module is added to the model. Through analysis and verification, the model has good generality and extension, which can provide theoretical basis for the matching design of various systems in the initial stage of pure electric vehicle, and can realize the effective analysis of the power and economy of pure electric vehicle.