Abstract: AC plasma vertical welding method with ER5356 filler metal was used to weld 8 mm 5052 Aluminum Alloy plate. By rational design of welding procedure and strict control of welding factors,the good welded joint properties of 5052 aluminum alloy was obtained. The results show that AC plasma welding method is suitable for welding of 5052 Aluminum. According to the relevant standards,the mechanical properties of the welded joints were tested,the X ray inspection and the metallographic analysis were used to analyze the welded joints. Results show that the bending and tensile properties of welded joints meet the requirements of the test standards. There is no porosity,slag inclusion and other defects in the weld,and the matrix of the weld is the microstructure of alpha（ Al） solid solution.