Abstract: Considering the characteristics of air defense weapon station ac servo system including large change range of load, intense disturbance torque when launching and high requirement for tracking accuracy, a position controller based on fuzzy adaptive sliding mode was designed. Sliding mode control can restrain influences of parameter uncertainties and external disturbance while fuzzy rules can adjust reaching speed adaptively and reduce chattering of sliding mode control. Simulation analysis and experimental results show that the proposed approach can guarantee the static and dynamic characteristics and the system possesses strong robustness against load disturbance and parameter perturbation. The results can provide a reference for practical application of advanced intelligent algorithms.