This article studies the use of a two-electrode gas shielded welding system to separate the heat source of the molten wire from the heat source of the base metal to reduce the arc energy concentration and the impact of the droplets. The author studied the relationship between the direct current path and thermal performance by comparing the actual heat input of TIG welding and MIG welding with the actual heat input of single arc welding. The direct current path between the two electrodes ensures the stability of the arc in the double arc welding, and a defect-free welding joint can be obtained. At the same time, the time of the double electrode double arc welding is greatly reduced. Taking magnesium alloy welding as the research object, the welding parameters can be optimized, and the microstructure of the welded joint can be analyzed. The author determined the best parameter configuration based on the analysis results, and further studied the effect of the addition of active agent on the performance of double arc welding.