Compound axis control technology has the advantage of high-precision dynamic tracking, and is widely used in high-precision electro-optical tracking system, laser communication and other fields. For the applications of airborne and shipboard platforms, the compound axis control system will be seriously affected by the disturbance torque. In order to overcome the influence of the disturbance torque, this paper applies the disturbance observer to the compound axis control to improve the precision of the compound axis control system. The simulation and analysis of the improved compound axis control system prove the effectiveness of the method. © 2019 IEEE.