Abstract: Taking a turning process of aeronautical case parts as an object, combined with the mechanical simulation of cutting process and finite element analysis method, the prediction of machining deformation during turning machining is realized. Then, the cutting parameter optimization is studied with the back-feeding knife as the design variable, the machining efficiency as the objective function and the machining deformation as the constraint. The integer programming optimization method changed the number of passes and reasonable. By assigning the amount of back-feeding knife perpass, the amount of machining deformation is reduced, the cutting efficiency is improved, and the efficient cutting of the aircraft parts is realized.