Abstract: Aiming at the unbalanced torque in the radar servo system, an active disturbance rejection control (ADRC) method is proposed based on load torque feed-forward compensation. The ADRC technology is applied to the speed loop control instead of traditional proportion integration differentiation (PID) controller in order to improve the robustness of the control system . Meanwhile,reduced order load torque observer is designed to estimate the load torque, and the observed value is used for compensation of the current loop controller to realize quick response to load disturbance. The simulation and experiment results show that the proposed control strategy can effectively suppress the disturbance of the unbalanced torque and improve the robustness of the control system.