The permanent magnet synchronous motor (PMSM) speed control system is easy to be affected by external load disturbance, this paper presents a fixed-time model-free sliding mode control strategy for PMSM based on improved sparrow search algorithm. Based on the input-output ultra-local model of the speed loop, a fixed-time sliding mode speed controller is constructed, and a fixed-time disturbance observer is designed to estimate the unknown disturbances of the ultra-local model, and through the way of feed-forward compensation to weaken the adverse effect of unknown disturbance on the speed control system, and improve the anti-interference ability of the speed control system, the fixed-time convergence of the speed controller and the observer is proved by Lyapunov function. In order to obtain the parameters accurately, an improved sparrow search algorithm is proposed to optimize the parameters of the controller. The experimental results show that the control scheme proposed in this paper effectively solves the overshoot problem compared with the PI control, accelerating the stability time by 22. 8% and reducing the loading speed change by 75%, indicating the effectiveness of the proposed control scheme.