Aiming at the problem of speed fluctuation and instability when the permanent magnet synchronous motor (PMSM) is suddenly loaded,a sliding mode speed regulation method based on integral time-varying sliding mode surface and a new fuzzy gain reaching law was proposed.A time-varying term was added to the traditional integral sliding mode surface by using the integral time-varying sliding mode surface to improve the response speed of the system.The traditional exponential approach law was improved by adding nonlinear functions to weaken the chattering of the system.At the same time,fuzzy algorithm was used to adjust the gain parameters of the approach law according to different system states,focusing on improving the approach speed and anti-disturbance ability of the system.Finally,Lyapunov stability criterion was used to prove the stability of the control system.The proposed control strategy was compared with the traditional sliding mode control strategy in MATLAB/Simulink environment.The simulation results show that the proposed control method has faster response speed,stronger ability to suppress system disturbance and chattering,and better comprehensive performance.