The 2A14 aluminum alloy is widely used in aerospace industry,especially for the manufacture of rocket fuel tanks,due to its good mechanical properties and resistance to stress corrosion from -250 ℃ to 250 ℃. In this paper,3-mm-thick 2A14 aluminum alloys were welded by the VPTIG arc welding,which were used to study the nonuniformity of microstructure and mechanical properties. The results show that grains in the weld are dendritic equiaxed grains,while the solid solution zone are coarse. The overaging zone and the base metal are flat. The content of alloying elements in the matrix of the weld zone is low,therefore the solid solution strengthening effect is weakened. At the same time,eutectic structures precipitate along the grain boundaries. The content of alloying elements in the heat-affected zone and the base metal matrix is relatively high. It can be seen from the microhardness measurements that the weld is almost the weakest zone in the joint. Moreover,base on the regression analysis,linear correlations among the yield strength and microhardness are established,σ,0.2,=2.94 HV-78.71.