This paper studies the control of brushless DC motor based on fuzzy PI control method. In order to improve the dynamic stability and speed control performance of the motor, its mathematical model and operation characteristics are analyzed in this paper, and the fuzzy rules of the fuzzy controller and membership function of the fuzzy variables are optimized by the genetic algorithm. The simulation results show that the optimized fuzzy PI controller has no overshoot, faster response speed, stronger anti-jamming ability and better stability when sudden load is added.