Abstract: A fixed time control method based on a fixed time disturbance observer is proposed for the speed controller of permanent magnet synchronous motor(PMSM) speed control system, which has slow finite time convergence and depends on the initial state. Firstly, by designing an integral type non-singular fast terminal controller, singularity problems can be avoided while achieving fixed time convergence of speed controller errors, ensuring the stability of the convergence performance under different initial working conditions. Secondly, a fixed time disturbance observer is designed to estimate unknown disturbances and improve the anti-interference ability of the speed control system through feedforward compensation. The fixed time convergence of the controller and observer is proved using Lyapunov stability theory. The experimental and simulation results show that compared with traditional vector control and sliding mode control, the proposed control scheme improves stability time, solves overshoot problems, and also has better steady-state performance. This indicates that the proposed control strategy has the advantages of strong robustness, fast response speed, and high steady-state tracking performance.