The simulation system and working principle of the non grid connected hydraulic generation system were introduced. Then the mathematical modeling and Simulink simulation for the system were completed. The physical model of the system was established. Through the changes of the input pressure and flow rate of the hydraulic motor,the wind energy from nature could be simulated in this experiment.The results indicate that the efficiency of the permanent magnet generator under normal condition is higher,but the entire power generation system still has lower efficiency.