The linear phase-shifting transformer has the advantages of simple structure and realize equal shifting at any angle, and it is widely used in multiple superimposed inverter systems. However, it is easy for linear phase-shifting transformer to lead an end effect, which affects the working performance of the transformer itself. First of all, on the basis of the principle of magnetic circuit similarity, it is analyzed the similarity of the iron core magnetic circuit between the linear motor and the rotating motor in this paper. Secondly, it is obtained the value of output current harmonic content and system efficiency with changing the effective air gap length. Finally, it is analyzed the influence on the leakage flux at the end of the transformer by adding a magnetic isolation material to the side teeth. The simulation results show that it effectively weakens the influence of the side effect and improves the application performance of the linear phase-shifting transformer by the reasonable selection of effective air gap length and the addition of magnetic isolation materials.