A simulation analysis method of milling process has been proposed to achieve the prediction of machining deformation of curved thin-walled structures. The regression equation of cutting force are ??obtained by milling experiments under a series of different combinations of cutting parameters to provide the basis for the cutting force loading of simulation test. By using python language for secondary development of Abaqus simulation software, combined with the “model change” technology and three kinds of tool path，milling simulation analysis have been carried on for the machining deformation of curved thin-walled structure. The results indicate that: the deformation of stepped Symmetrically tool path has the minimum amount, and the amount of deformation of unilateral tool path pattern is much larger than two kinds of Symmetrically tool path , With the reduced height of the side walls, the difference decreases, and at the bottom, substantially the same amount of deformation obtained. Finally, The reliability of the simulation analysis milling experiments is verified by milling experiment.