Aiming at the problems of chattering and slow response in the speed control system of permanent magnet synchronous motor (PMSM),the sliding mode variable structure control method was used to design the speed loop controller.To improve the approaching speed of the system on the sliding mode surface,the traditional linear sliding mode surface was replaced by a non-singular terminal sliding mode surface.At the same time,a new reaching law was proposed which was based on the double power reaching law.In order to improve the reaching speed,reduce the system chattering and improve the convergence characteristics of the system,a switching function were introduced which included the terminal attractor,and the exponential term was added.The control algorithm was compared with the double power reaching law.The simulation results show that this method can be used to suppress the system 〖JP2〗chattering more effectively,improve the convergence speed of the system,and track the given speed signal more quickly and accurately.