In order to solve the transformer’s problems such as huge volume, heavy weight, large noise, and control is not flexible enough in the power frequency scheme of the flexible medium voltage DC power distribution system, a flexible medium voltage DC power distribution system based on high-frequency link DC solid state transformer is presented. The system of DC power distribution buses include not only medium voltage DC bus, but also low voltage DC bus; the medium and low voltage DC buses are connected via a DC solid state transformer; low voltage DC bus is used for access to all kinds of distributed power supply. In this system, the use of high frequency link DC solid state transformer not only realizes the voltage transformation, energy management between different voltage levels, but also effectively improves the system power density. The medium voltage flexible DC distribution system architecture is introduced, the high-frequency link DC solid state transformer and other typical converters are designed and analyzed, and the working mode of DC power distribution system and a controller are designed. Finally, the simulation platform is built to verify the effectiveness of the system. This work is supported by Projects of International Cooperation and Exchanges NSFC (No. 512111038).