Abstract: 7A52 aluminum alloy plate of 10 mm was welded by vapor plasma arc welding with ER5356 filler and 40% acetone H₂O solution.The mechanical properties and microstructure of the welded joint were studied.The results indicate that the welded joint shows sound mechanical properties.Micrograph analysis shows that the tensile fracture exhibits large quantities of dimples, which indicates good ductility of the weld.There is a softening zone in the HAZ.No abnormal porosity, inclusions and micro-cracks were found in the welded joint.Therefore, vapor plasma arc welding of 7A52 aluminum alloy can obtain excellent welded joint.