To meet the dynamic and steady performance requirements of the satellite attitude control system on the rotor speed of the Single-Gimbal Control Moment Gyro (SGCMG),a dual-mode control method based on genetic algorithm for quasi-dual-loop and phase-locked loop is presented,and the disturbance torque compensation control is introduced to realize the steady speed control of the rotor under interference.To simulate the current loop and speed loop control,the genetic algorithm is used to optimize the two sets of Proportional-Integral (PI) parameters to form a quasi-double loop controller with variable parameters.The dual-mode control consisting of the quasi-double loop controller and the phase-locked loop can realize high-precision control with fast response speed and low overshoot.For the problem that the rotation of the SGCMG frame disturbs the rotor speed,the causes of the disturbance are analyzed.The relationship between the frame speed θ· and the disturbance torque Td is derived by using experimental data.On the basis of the dual-mode controller,the angular rate feedforward controller is designed to suppress the interference in the form of torque compensation,and the fluctuation of the speed can be suppressed to 15% of that under no-compensation conditions.The steady-state error of speed is less than 0.045% when the desired speed is 4000 r/min.