In connection with high precision micro-feed and super low speed permanent magnet linear synchronous servo system (PMSLS), this essay adopts vector control to make up a three closed-loop system. The speed-loop and current-loop adopt IP controller, position-loop adopts second order sliding mode variable structure control to ensure fast tracking performance of system response, and then achieve high-precision micro-feed. In order to compensate friction disturbance and increase robustness, this essay adopts based on Genetic Algorithms friction model's parameter identification on line and feed-forward compensation. According to Simulation result, the system has high robustness and steady state precision was improved.