Abstract: In order to improve the position control accuracy, response speed, and disturbance resistance of the servo control system of the surface-mounted permanent magnet synchronous motor(SPMSM), a novel position loop control method with improved sliding mode control is proposed. On the basis of the position-current two-loop control model, the mathematical model of SPMSM under d-q axis is established; the sliding mode control combining the improved sliding mode surface and the new exponential convergence rate is adopted to weaken the sliding-mode jitter phenomenon. Then, Lyapunov′s second method is used to judge the stability of this control method. Finally, a simulation model is built using MATLAB/Simulink to compare and analyze with five control methods, which verifies the superior fast, accurate and stable performance of the method.