In order to analyze the influence of the milling process parameters on the residual stress of the machined surface of aluminum alloy, according to the related theories of metal cutting finite element analysis, the aluminum alloy 6061 was used as the workpiece material, and the finite element model of milling was established. The single factor method is used to simulate the mirror milling of aluminum alloy 6061, and the influence of different spindle speed, milling depth and milling path on the surface residual stress of aluminum alloy 6061 is analyzed. The research shows that during the processing of aluminum alloy 6061, the influencing factors on the surface residual stress of the workpiece in descending order are milling depth < milling path < spindle speed. The spindle speed has the greatest influence on residual stress of the machined surface, and the optimal group of mirror milling reduces the deformation displacement by 33%  compared with ordinary milling.