Abstract: The speed control system of a permanent magnet synchronous motor based on model predictive current control often exbits unstable operation and speed fluctuatation under external disturbance. We propose a discrete sliding-mode control for a permanent magnet synchronous motor model, based on predictive current control with a load disturbance observation. Based on the current predictive control algorithm for a surface permanent magnet synchronous motor, we design a discrete sliding-mode speed controller to replace the PI regulator, suppress the overshoot, and improve the starting performance of the system. We propose a discrete sliding-mode perturbation observer and use it for feed-forward compensation. The observer suppresses the external disturbance effectively and improves the robustness of the system. The simulation shows that this control strategy can improve the system's dynamic performance and steady-state precision.