In order to shorten the response time of permanent magnet synchronous motor,improve the dynamic performance,steady-state accuracy and robustness of the system,a control system combining cascaded extended state observer and adaptive non singular fast terminal sliding mode control was designed.Firstly,based on the mathematical model of the motor,a cascaded extended state observer was established,which can accurately observe and compensate for disturbances,optimizing the dynamic performance,steady-stateaccuracy,and robustness of the system.Secondly,a new type of non singular fast terminal sliding surface and approach rate were designed in the speed loop,which can effectively suppress speed overshoot and chattering phenomena in PI control and achieve fast convergence.In the controller design,considering that the observer estimation error is unknown,an adaptive law is designed to adjust the unknown estimation parameters.Finally,a rigorous stability analysis was conducted on the proposed control strategy. The simulation results show that compared with traditional control methods,the speed overshoot suppression ability is improved by 9.6%,and the speed fast response ability is improved by 0.045 s,with excellent speed dynamic performance and anti-interference ability,which improves the performance of the system.