Considering the problems that position servo system of air-defense multiple launch rocket system (MLRS) is strong coupling, variable loading and nonlinear, and an approach based on adaptive fuzzy sliding mode control with integral sliding surface was proposed. In order to make that control law be independent of accurate mathematical model of the object, principle of universal approximation of fuzzy systems was utilized to design a fuzzy system to realize the approaching of ideal control law. In order to reduce chattering, the adaptive law based on switching gain was designed to realize the dynamic adjustment of system parameters. Simulation results show that this method guarantees the static and dynamic qualities of system effectively weakens the chattering of control signal and has strong robustness to parameter uncertainty.