Carbide, TiN coating and TiAlN coating three tools were carried out for dry milling test of 2198-T8 aluminum lithium alloy, the machining surface quality and milling force data were obtained under different parameters and coating tool, chip characteristics was also observed and analyzed. The results show that when milling aluminum-lithium alloys, the main wear of the tool for adhesion wear, TiN coating adhesion degree is the lowest, followed by carbide, while surface adhesion of TiAlN coating tool is the most serious, the lowest cutting efficiency. The adhesion wear seriously affects the surface roughness of the milling forming, and increases the milling force; milling speed is the main factor affecting the surface roughness, by increasing the milling speed can reduce the degree of material adhesion, reduce the surface roughness and milling force, TiN coating in milling aluminum lithium alloy when the minimum surface roughness can reach 0.5 μm below. Under the same cutting parameters, the TiN coating chip breaks evenly, the chip surface is relatively smooth, and the chip plastic deformation is minimal; the chip produced by carbide tools has a short chip size, and there are a few stripes chip on the surface, and the chip produced by TiAlN coating tools undergoes serious plastic deformation. Compared with TiAlN coated tools, TiN coated tools have the best cutting efficiency and can achieve the best surface roughness and machining effect.