This paper proposed a new interleaved three -level converter with dual transformers, which was realized by paralleling an auxiliary bridge arm to the main bridge arm and series connecting the secondary side of the auxiliary transformer series to the primary side of the main transformer.The advantages of traditional three-level converter were maintained, and wide range output voltage was obtained through the on/off of auxiliary arm. It analyzed the working principle of dual transformer three level converter, compared the efficiency of the converter and the traditional converter in different output range. Finally, a prototype of 1500W was built to verify the correctness of the theoretical analysis and the feasibility of the new converter.