Abstract: The elastic deformations of flexible bodies couple with the rigid motions of rigid bodies in light-duty and high-speed equipments, and have obvious influence on the dynamic precision of the equipment. The mini-type satellite radar is investigated to analyze the influence of torsional vibration of two drivers on the dynamic precision of the radar, while the second driver was moving. It is illustrated that there exist torsional vibrations attenuated by damping on the two drivers, which has little apparent influence on the precision of the radar mirror. The influence could be compensated by control feedback.