5A06 aluminum alloy sheet welding with traditional TIG and MIG welding technology is usually inefficient and results in poor mechanical performance as well as cannot meet requirements. For this critical problem,the DC double pulse MIG welding experiments of 5A06 aluminum alloy sheets were carried out. The effects of DC double pulse MIG welding technology on the microstructure and mechanical properties of the welded joints were investigated by optical microscopy,scanning electron microscopy and tensile testing machine. The results show that when the wire feed speed is 5 m/min,welding speed is 50 cm/min,pulse frequency is 3 Hz,wire extension is 12 mm,and protective gas is high purity Ar gas with a flow rate of 25 L/min,the beautiful weld surface with fish scale figure are obtained,there is a large amount of the fine equiaxed grain in weld zone and the gas pores in the weld cross section reduce.The welded joint has good tensile property,and tensile strength of the welded joint is above 90% of the base metal.