Abstract: Aiming at the poor speed regulation performance and insufficient anti-interference ability of permanent magnet synchronous motor existing in the traditional PI control, this paper designs a new type of composite control scheme—sliding mode self-immunity control based on load torque observer in the speed outer loop and current inner-loop deadbeat control. In the rotational speed ring, the sliding mode algorithm is introduced to design the nonlinear error feedback control law to improve the response speed of the self-immunity control, and at the same time, to adapt the actual working environment, the load torque observer is designed to compensate for the expansion observer and to improve the accuracy of the disturbance observation; in the current ring, the current is designed to be tracked accurately by the deadbeat control, which makes the dynamic performance of the motor and the quality of the current to be improved. Simulation results show that the new composite control strategy proposed in this paper has significantly improved the comprehensive performance and anti-interference ability of the permanent magnet synchronous motor, and effectively reduces the adverse effects of the complex working condition environment on the motor.