Abstract: In view of the problems that multiscale interaction is difficult to be separated and integrated in the modeling process of power electronic converters, by introducing the multiscale concept into the modeling process, a scale division method and a multiscale modeling method suitable for power electronic converters are proposed. Furthermore, in order to solve the convergence problem of information interaction between scales, and the contradiction between calculation accuracy and calculation efficiency, an interaction strategy for multiscale model is proposed, and the multiscale simulation of typical converters is realized by calling MATLAB and COMSOL software. Finally, compared with the ideal model, the multiscale modeling method and the interaction strategy can effectively reflect the multiscale and multiphysics phenomena in power electronic converters. The results show that the multiscale model is a general description of power electronic converters, and the ideal model is a special case of the multiscale model.