Motor is the sole power source of electric vehicle, whose reliability and fault tolerance are directly related to the performance of electric vehicle. Considering the motor can't keep constantly normal operation as one-phase open-circuit fault occurs, six-phase permanent magnet synchronous motor (PMSM) with fault tolerance is designed in this paper. Firstly, the designed six-phase fault-tolerant PMSM is verified by the finite element method through the simulation software AnsysMaxwell. Then, the torque output of the six-phase fault-tolerant PMSM is analyzed at the regular state and the occurrence of one phase open circuit fault. Finally, in order to reduce the torque ripple of the fault-tolerant motor, the motor parameters are optimized. The feasibility of the proposed scheme is verified, and the safety of the electric vehicle is improved.