A permanent magnet linear synchronous motor (PMLSM) vector control system based on sliding mode variable structure was designed. Proceeding from the basic work principle of the PMLSM, and then according to the coordinate transformation, the mathematical model of it is established in the two phase synchronous rotating orthogonal coordinate system. The speed regulator was designed based on the sliding mode variable structure and Lyapunov stability theory, which was composed of the PMLSM vector control system based on sliding mode variable structure. In order to demonstrate the effectiveness of the control system, the model of whole system was built and carried out based on the MATLAB/Simulink. Simulation results verified the control system had strong robustness.