Based on the simulation of electric vehicle (EV), the parameter design methods and winding switch characteristics on the driving permanent magnet brushless direct current motor (BDCM) are studied. First of all, the mathematical model of the BDCM when used to drive the EV is established, then effects of the EV velocity and the motor's leakage inductances on the current trace ability, torque production and then the EV performance are studied. In order to improve the EV performance, the winding switch strategy of the BDCM is presented. By high-velocity speed-up simulation and stable running one of the EV driven by BDCM with winding switch, the motor's design criteria is given.