Abstract:  Cold metal transfer+pulse welding (CMT+P) of 5083 aluminum alloy sheet was carried out in this paper. The microstructure and mechanical properties of welding joint were investigated using scanning electron microhardness, microhardness tester and tensile testing machine. The results show that the welding bead was well formed. The weld microstructure is as cast equiaxed dendrite, the heat affected zone microstructure is the mixed structure of processed fibers and local equiaxed grains and the base metal is still rolled fiber structure. Bone-like or block iron rich impurity phase AlFeMn were found in welded joints and heat-affected zones. Compared with the base metal structure, the grain size of the weld area is 46.31μm, and the proportion of large-angle grain boundaries is 16.43%. The hardness of the weld area is 77~81HV, and the tensile strength of the welded joint is 295 MPa, which is 89.39% of that of base metal . Elongation after fracture reaches 15% , which is 75% of the base material.