In the AC servo system of a rocket launcher, it is difficult for the traditional PID control method to get good performance due to the complex nonlinearity of the moment of inertia, friction, variable loads and internal and external disturbances under different working conditions.To solve the problem, we established the mathematical model of the AC servo system of rocket launcher according to its composition, and designed a Fractional Order PID (FOPID) controller based on neural network Active Disturbance Rejection Control (ADRC).In order to reduce the parameters'calculation cost of the fractional order controller and improve its dynamic performance, a control algorithm of Radical Basis Function (RBF) neural network is adopted for on-line self-tuning of the two parameters of FOPID, integral order and differential order.The simulation test results show that the control strategy can effectively suppress the position disturbance with fast response speed and no overshoot.