This paper introduces the preparation of the electromagnetic field analysis with APDL language universal program steps and processes , for a typical Boost switch power circuit is given as an example to introduce how to model and post-processing analysis with universal program, The simulation results under ANSYS environment are compared with the simulation results under the MATLAB environment, the simulation results are basically the same in two kinds of different simulation environment, the universal program is an effective analysis method to analysis of the switching power supply electromagnetic field. APDL language has been used in switch power electromagnetic field analysis, one shorten analytical calculation time greatly and improve calculation accuracy, the other shortened the development cycle of the switching power supply and improved work efficiency, with a larger engineering practical significance.