Abstract: Aimed at the problems of the integer-order sliding mode control under the direct force control of the permanent magnet linear synchronous motor (PMLSM) that the accuracy of the speed loop is not high and the flux linkage and the thrust fluctuation are large, an improved fractional-order sliding mode control algorithm is proposed. The combination of the double-power exponential reaching law and the fractional variable speed reaching law could effectively reduce the system oscillation caused by sliding mode control and accelerate the approach rate. The simulation results show that compared with integer-order sliding mode control, when the improved fractional-order sliding mode control is adopted in the PMLSM direct force control system, the flux linkage and thrust fluctuations are significantly reduced, the system response speed is accelerated, and the anti-interference ability of the PMLSM thrust response is improved.