In the future,power by wire will replace traditional hydraulic transmission in aircraft.Electro hydraulic actuator(EHA) has attracted more and more attention.In order to solve the disturbance of electro-hydrostatic actuator in aircraft,a position servo control system was designed based on active disturbance rejection control.Taking a EHA as the object,the position outer loop of the actuator was modeled and analyzed,and the second-order state space model of EHA position servo system was obtained.Based on the model,the structure of position servo active disturbance rejection controller was designed,and the nonlinear function was optimized.It was compared with the traditional PI controller under sinusoidal disturbance and sudden disturbance.The simulation results show that the algorithm improves the anti-interference ability of the system on the premise of meeting the dynamic performance of the system.