Abstract: In order to achieve high quality machining of aluminum alloy precision parts, the influence law of cutting speed, spindle speed, back cutting capacity and side cutting capacity on surface roughness of 7075 aluminum alloy was analyzed through milling test and surface morphology observation. The prediction model of surface roughness was established based on multiple linear regression analysis. A multi-objective optimization model with the highest material removal rate and the lowest surface roughness was established by taking the amount of milling as the constraints. The optimal solution of the multi-objective optimization model was obtained by using the multi-objective linear programming method, and the correctness of the optimal solution was verified by experiments.