In order to further suppress the chattering problem of permanent magnet synchronous motor (PMSM) speed control system, a fuzzy sliding mode speed controller based on particle swarm optimization algorithm was proposed on the basis of exponential reaching law Sliding mode control (SMC). This method first uses Particle Swarm Optimization (PSO) to preliminarily tune and optimize the sliding mode parameters; Then, a new exponential approach law is designed, which introduces system state variables and fractional polynomials containing exponential terms in the constant velocity term of the exponential approach law to accelerate system convergence speed and reduce overshoot; Finally, fuzzy control is used to dynamically adjust the constant velocity term parameters, further improving system performance. The simulation results show that the fuzzy Sliding mode control based on PSO has better response performance than the exponential approach law Sliding mode control. The overshoot and speed fluctuation are reduced by 18.96% and 0.8r/min respectively, and the chattering suppression ability and dynamic performance are improved.