Abstract: This paper focuses on the design of an antenna pitch servo system. The entire article first introduces the overall scheme of the pitch servo system, which is mainly composed of the pitch mechanism subsystem and the drive control subsystem. Then, mathematical modeling is carried out on the controlled object of the system, including the establishment of mathematical models for the motor and mechanical transmission. To overcome the nonlinear and interference characteristics of the system, this paper innovatively adopts a three loop proportional-integral-derivative control scheme based on nominal point and disturbance observer for control system design, mainly focusing on the design of current loop corrector, speed loop corrector, position loop corrector, and disturbance observer. Finally, simulation verification was conducted, and the simulation results showed that the designed control system has good position tracking performance and robustness; and through practical experiments, it was further verified that the designed servo control system has good pitch angle position tracking performance.