Abstract: A modular multilevel DC transformer structure for power distribution system was proposed and analyzed in this paper. The proposed converter adopts only one high frequency transformer to realize galvanic isolation and voltage matching, which dramatically simplifies the insulation design. To improve the power efficiency and achieve balanced submodule voltage, a dual phase shift method was proposed. The operation principle and control strategy were presented in detail. The soft switching characteristics of power semiconductors were discussed. To verify the converter and the control method, a 2 k W down-scaled prototype based on silicon carbide device was constructed. The experimental results comply with the theoretical analysis very well.