A decentralized control scheme based on backstepping design is proposed in this paper for the grid converters of a multi-terminal dc power integration system. With the proposed method, dc bus voltage can be accurately maintained together by several converters through appropriately adjusting their transmitted power according to the power sharing ratio. The system structure is presented and its dynamic model is formulated. The decentralized control laws of the grid converters are developed step by step by designing appropriate Lyapunov functions. The dc bus voltage control and the power sharing performance of the proposed control method are evaluated both under the system normal condition and converter fault condition. Finally, the effectiveness of the proposed scheme is validated through the real-time simulations on NI-PXI platform.