Abstract:During precise attitude orientation control of large flexible spacecraft in space, the vibration of actuators and deformation of flexible structures would bring high and low frequency disturbance to orientation control of the load. In allusion to this problem, a multi-loop combined control strategy is promoted. Beyond the basic attitude control loop, an actuator vibration isolation loop and a load precise orientation control loop are introduced, which are used to isolate the vibration of actuators and to precisely compensate for load orientation separately. The control method of each loop is also designed. The results of simulation and some test show that this method is effective to improve load orientation accuracy.