Abstract: The spray formed and hot extruded 7055 aluminum alloy with 3 mm thickness in annealed state was welded by filler wire TIG welding, and the microstructure of the welded joint was observed by metalloscope, the mechanical properties of the welded joint were tested by tensile and microhardness tests, and the fracture morphology was observed by scanning electron microscope. The results show that 7055 aluminum alloy welded joint with good forming can be obtained by TIG welding with ER5356 filler wire, and the microstructure of the weld and the fusion zone is coarse dendrite and fine equiaxed grain respectively, the width of heat-affected zone reaches 22 mm and the grains of HAZ near the weld are flat layered shape,and the structure is coarened obviously, and the base metal retains the original spray deposition structure. The microhardness curve is M-shaped and the two peaks are both located in HAZ near the weld. The average tensile strength of the joint is 190MPa, and the average elongation is 6.76 %. The fracture of the joint is ductile-brittle mixed fracture.