Abstract: The actual experiments of three-phase circuit are always dangerous for students in the laboratory. Especially the fault experiments are difficult to carry out. In view of the above problems, this paper uses circuit simulation software, multisim to design a three-phase circuit connected by wye-connection and delta-connection, analyze the influence of load change on three-phase circuit and improve the power factor of the three-phase circuit, and design three-phase circuit under short circuit and open circuit fault. Through the above experimental design and simulation analysis, the three-phase circuit design based on Multisim software can verify the basic principle of three-phase circuit, and provide a new method for the experimental design of fault circuit of three-phase circuit, which can be used in the teaching of electrical and electronic experiments in colleges and universities.