Double-electrode gas metal arc welding (DE-GMAW) was recently developed to control the current through the workpiece at a desired level when the welding productivity was increased. A novel welding method entitled consumable double electrode with a single arc GMAW (consumable DESA-GMAW) was proposed to further enhance the welding productivity by replacing the non-consumable electrode in DE-GMAW with a consumable electrode. The consumable DESA-GMAW system can work stably with appropriate welding parameters. In this paper, the effects of control variables including the voltage of the main power source and slave power source as well as the wire feed speed of the main wire and bypass wire on the current distribution between the workpiece and bypass wire were studied. The effects of the variables on arc behavior and metal transfer process were also studied. The ratio of the current through the bypass wire to the main wire can be increased by decreasing the main power source voltage, increasing the slave power source, or increasing the main wire feed speed. However, a higher ratio obtained by modifying a single control parameter may negatively influence the regular metal transfer process.The ratio of the current through the workpiece to the main filler wire can be most effectively decreased with a combination of relatively lower main power source voltage and higher slave power source voltage.