Friction torque is an important parameter affecting the servo system, which will decrease with the increase of service time. With the change of friction torque, the control characteristics of the servo system will change, resulting in the servo dynamic and static performance can not meet the system requirements. On the basis of expounding the composition and working principle of gun pitching servo system, a control method of gun servo system based on fuzzy adaptive control is proposed. The problem of system performance change caused by the change of servo system parameters is solved. Through MATLAB simulation, it shows that the method can eliminate the influence of friction torque change on the system, make the system insensitive to the change of torque parameters, and meet the use requirements under various parameter conditions.