In this paper, the finite element software COMSOL is used to establish a two-dimensional simplified vacuum arc model, and the parameters are set in COMSOL to set the conditions. A transverse magnetic field is applied between the two contacts, and the transverse magnetic field can cause the arc to burn in one direction, reducing the ablation of the contacts by the arc. In this paper, the process of arc motion under different magnetic field strengths is studied. The trajectory of arc motion can be seen, reflecting the movement state of the arc at different moments and the comparison of the maximum contact temperature.