Considering the space application of the double gimbal moment gyro (DGCMG), the coupling moment of gimbals and gyroscopic torque caused by spacecraft leads to a velocity ripple of the gimbal. In light of this problem, the dynamics model of the gimbal system of the DGCMG used in spacecraft is set up, and a disturbance observer is proposed based on the extended state observer (ESO). The integrated disturbance torque can be estimated by the extended state observer. Then, the disturbing moment is compensated using torque feed-forward. Both simulation and experimental results show that the control algorithm effectively suppresses the velocity ripple caused by the disturbance torque and improves angular precision of the gimbal.