Abstract: The interference between the power supply and the distribution equipments in the spacecraft becomes more and more a serious issue, due to the development of the multi-cabin spacecraft and the increasing numbers of power supply and distribution equipments in the spacecraft. As a result, the primary busbar grounding design in different cabins of the spacecraft appears especially important. Based on the grounding strategy, this paper presents a primary busbar grounding design scheme in different cabins of the spacecraft, together with the practical applications.