To meet the needs of its characteristics, this paper studies the space high voltage power conversion system’s circuit topology and the optimization design of its structure. In the first part, the Common space solar power station power management and distribution methods is analyzed. And based on that, a new hybrid power system structure is presented, in which a power transmission bus-bar structure suited for space solar arrays is constructed and the modular multi-converter with serial-parallel combination control strategy is proposed. By applying this new structure, the high transformation ratio in the solar cell arrays and sub-arrays, the low power loss, the large power conversion with high power density and the high efficiency can all be achieved. In the second part, a new soft-switched isolated full-bridge converter is also proposed. And researches is made based on the new converter, which includes the study on the transformer modular magnetic integration, the space temperature field and the thermal design. finally, the simulation and experiment prove the correctness of the theoretical analysis.