A novel spacecraft using Stewart vibration isolation platform is discussed and applied to improve the performance of precision payloads in this paper. Firstly, the structural architecture of the Stewart spacecraft is implemented and the advantages are introduced. In this new architecture, the voice coil actuator which is structurally separated is adopted, and then the payload is free of all the vibrations transmitted from the vibration equipments. Secondly, the dynamic model of the Stewart spacecraft is established and the disturbance free characteristics are analyzed. Thirdly, the high accuracy attitude control strategy is designed based on sliding mode control algorithm. Finally, simulation results are illustrated to demonstrate the effectiveness of attitude control, and furthermore, to demonstrate the validity of the proposed Stewart spacecraft.