In order to solve the problem of weak anti-disturbance and poor tracking accuracy of conventional three-ring servo system, this paper optimizes the conventional servo system with the aid of tracking differentiator and load observer. The tracking differentiator unit of anti-disturbance control technology is used to plan the trajectory and acquire the information of load mutation, and the load observer is introduced to observe the slow load fluctuation. The experimental results show that the anti-disturbance performance of the new designed servo system is greatly improved, and better effect is obtained in improving the tracking accuracy and reducing the mechanical impact.