A lase stereo forming method for aluminum alloy thin-wall part relates to a laser material increase manufacturing method for aluminum alloy parts. The invention solves the technical problems of collapse and porosity in the manufacturing process of aluminum alloy thin-wall parts by laser stereo forming. 1, clean that substrate; 2, dry that powder; 3. Manufacture of lase augmented material. The invention can effectively solve the collapse problem of the aluminum alloy in the laser stereo forming process, The aluminum alloy parts printed by the laser stereoscopic forming method of the aluminum alloy thin-wall parts of the invention have stable lifting height of each layer, can be stably grown for more than 200 layers, the internal pore diameter is less than 0.2 mm, the density of the formed parts is more than 99%, and the thickness of the aluminum alloy thin-wall is 1 mm to 3 mm.