Abstract: The side-deflection of weld section in cable type welding wire GMAW will lead to poor fusion of welded joints. Therefore, based on droplet force analysis and the principle of minimum voltage, the mechanism analysis of the change rule of the side-deflection of weld section was carried out. The results show that the current is the key factor affecting the side-deflection of the section. The unique stranded structure of the cable type welding wire causes arc rotation, which leads to the phenomenon of uneven force on the droplet. The transition direction of the droplet is at an angle with the axis of the welding wire, resulting in the phenomenon of side -deflection of the weld section under the action of the droplet impact force. The droplet transition direction gradually tends to the axis, so the side-deflection trend of weld section decreases with the increase of current.