CVVL motor is a permanent magnet brushless DC motor used to improve engine performance and reduce vehicle fuel consumption. With the CVVL motor as the optimization object in this paper, the optimization variable is based on five structural parameters of the permanent magnet thickness, the outer diameter of rotor, the inner diameter of stator, the stator slot body width and the stator slot height, and improving rated torque and motor efficiency, reducing torque ripple and stator slot full factor are optimization objectives. Based on the platform of simulation software ANSYS, the multiobjective optimization of permanent magnetic brushless DC motor structure has been done, and the optimal solution set is obtained. Finally, the feasibility of the optimization method is verified by simulation and test, and the results show that the optimized motor performance is improved to meet the optimization target. The multiobjective optimization method in this paper can provide the reference for the structural optimization of permanent magnetic brushless DC motor.