对3 mm厚5083铝合金和16 mm厚6063铝合金进行双丝冷金属过渡（CMT）角接焊，通过分析焊缝成形性能和抗拉力确定了最佳焊枪角度、焊接速度以及后丝焊接电流等参数，研究了最佳参数焊接后接头的显微组织和硬度。结果表明：最佳工艺参数为焊枪角度60°、焊接速度2.0 m·min^-1、后丝焊接电流140 A，所得焊缝表面过渡圆滑，无咬边、驼峰等缺陷，单位长度拉力最大，为548.7 N·mm^-1；5083铝合金侧熔合区和热影响区界线分明，热影响区中的杂质相在晶界上富集，6063铝合金侧熔合区较窄，焊缝组织由枝晶组成，且出现晶粒大小不同的条带组织；焊缝区硬度最高，熔合区和热影响区未发生硬化或软化。

Twin-wire cold metal transfer (CMT) fillet welding was conducted on 3 mm thick 5083 aluminum alloy and 16 mm thick 6063 aluminum alloy. The optimal parameters, including torch angle, welding speed and back wire welding current, were determined by analysis of the weld formation and tensile resistance. The microstructure and hardness of the joint welded with the optimal parameters were studied. The results show that the optimal process parameters were listed as follows:torch angle of 60°, welding speed of 2.0 m·min^-1 and back wire current of 140 A. The obtained weld surface had a smooth transition and no defects such as undercuts and hump; the tensile force per unit length reached the largest value of 548.7 N·mm^-1. The boundary between the fusion zone and the heat affected zone at 5083 aluminum alloy side was distinct, and the impurity phase in the heat affected zone was enriched at the grain boundary. The fusion zone at 6063 aluminum alloy side was narrow, and the weld structure was composed of dendrites and had a strip structure with different grain sizes. The weld zone had the highest hardness, and the fusion zone and heat affected zone were neither hardened nor softened.