Abstract: Single gimbal control moment gyro(SGCMG) servo system is studied.Permanent magnet synchronous motor(PMSM) in the system is driven with sine wave;vector control strategy is used to control the inverter in the internal current loop;the external position loop is designed with fuzzy adaptive sliding mode control(FASMC) that fuzzy adaptive method is applied to regulate the gain of switch control variable.The simulation demonstrates that the system with FASMC controller has a high dynamic and steady precision, and is also robust.At the same time, the quiver brought by conventional sliding mode control is greatly weakened.