Abstract: To address the high power demand, significant energy consumption, and elevated costs in testing medium-voltage high-power DC–DC converters, this paper proposes a high-power DC back-to-back testing platform based on a hybrid clamping topology. First, a DC back-to-back system composed of two DC–DC converters is constructed. On this basis, a high-power DC–DC converter employing a hybrid clamping structure combined with a quasi-two-level modulation strategy is used to build the testing platform. Finally, PLECS simulations are conducted to validate the operational performance of the proposed platform. The results show that the platform can achieve high-power testing under low external power supply conditions and demonstrates good engineering applicability.