The working principle of permanent magnet synchronous motor (PMSM) vector control system is analyzed. For the disadvantages of traditional PI regulator, like the long regulation time and high degree of dependence on motor parameters, a strategy of single step model algorithm is used. A PMSM vector control system based on single step model algorithm is designed, and the system is simulated and analyzed. The simulation results demonstrate that the single step model algorithm control has advantages of low dependence of motor mathematical model, less influenced by uncertainties. In the dynamic process, the system has a better rapidity of dynamic response and a smaller overshoot, and has strong robustness to load disturbance.