In order to improve anti-disturbance and control accuracy of permanent magnet direct drive wind generation system, a maximum power tracking control strategy based on non-singular fast terminal sliding mode control with disturbance observer is proposed. The torque of the wind turbine is estimated by the disturbance observer, and the feed-forward compensation of the controller is realized. The non-singular fast terminal sliding mode with improved reaching law is adopted to enhance the dynamic performance of the controller, which ensure the limited time convergence of the system and reduce the chattering infuences caused by disturbance. Simulation results show that the torque change can be accurately estimated under variable wind speed by the proposed strategy, and speed tracking accuracy and wind energy utilization can be improved during maximum power tracking.