In recent years, as the proportion of renewable energy generation in the power generation system is more and more, to improve operation capacity of the grid, power electronic transformers (PET) are widely used in the distribution network. As the core equipment, power electronic transformers need to connect more feeders to meet the requirements of various sources and various loads. This paper proposes a multi-port PET and designs corresponding control strategies for different power stages. Compared with traditional PET, it is smaller and more convenient to control. Finally, the proposed multi-port power electronic transformer model is built in the PLECS simulation platform. The results suggest that the designed control strategy could well stabilize and balance the DC voltage, regulate the power flow between multiple ports and has a certain fault isolation function.