Controlling the shape of the welding arc by applying a transverse magnetic field is an important research field of magnetron welding technology. In this paper,the transverse magnetic field is applied to change the arc energy distribution and arc shape change to explore the effect of the applied magnetic field on the arc shape and the excessive droplets. The results of the study show that,while maintaining the original bell-shaped shape of the MAG welding arc,the end dragged behind. At the same time,the addition of transverse magnetic field accelerates the excessive frequency of droplets and shortens the period of excessive droplets.Trailing after the end of the arc can effectively inhibit the liquid flow in the molten pool and improve the weld formation.