This paper addresses the multibody dynamics and robust attitude control of a MW-level solar power satellite, which mainly consists of an 800-m-length center truss, a 150-m-diam microwave-transmitting antenna and twenty-four 25 × 100 m solar subarrays. Based on the selected reference attitude and the floating frame formulation, the flexible multibody attitude dynamic model is firstly derived by Lagrange equations in terms of quasi-coordinates. The gravity-gradient, solar radiation pressure, and microwave radiation torques are also investigated to evaluate their influence on attitude control accuracy. Then, a hybrid high/low bandwidth robust controller is proposed. The rough attitude control of the center truss and solar subarrays is achieved by the low bandwidth control, which combines the feedback linearization with the disturbance observer and minimizes the control-structure interaction of the center truss. The precise antenna pointing control is achieved by the high bandwidth collocated control, where the optimal locations of actuators/sensors are obtained by minimizing the influence of the attitude control system on the structural vibration. The fully coupled nonlinear numerical simulation are finally provided. It is demonstrated that the proposed controller can guarantee attitude control performance of all component structures.