Residual stress generated during the cutting process is one of the main factors causing deformation of thin-walled parts. The selection of cutting parameters has a direct impact on residual stress. By analyzing the variation law of residual stress and selecting cutting parameters reasonably, surface residual stress of the workpiece after cutting can be reduced, ultimately achieving the goal of controlling the degree of deformation of thin-walled parts and ensuring machining accuracy. Researches have been conducted on certain aspects, including change laws and influences of cutting force, cutting temperature and residual stress on the forming qualities of thin-walled parts. Based on previous studies, this paper proposed an improved algorithm to analyze the residual stress and optimize the process during formation of the thinwalled parts. Firstly based on McDowell model, this study established a theoretical model for three-dimensional residual stress, and analyzed the influence of spindle speed, feed rate per tooth and axial cutting depth on residual stress under highspeed cutting conditions through milling simulation; the results showed that the feed rate per tooth had the greatest impact on residual stress. Then based on the theoretical model and simulation analysis results, with the optimization objective of reducing residual stress and simultaneously increasing material removal rate, the Pareto simulated annealing algorithm was used for dual objective optimization of cutting parameters, and a set of optimal solutions was obtained. Finally, the optimization results were verified through milling experiments, and results showed that the error rate between residual stress values solved by the optimization algorithm and those measured by the experiment was within a reasonable range, indicating reliability of the optimization results and feasibility of the optimization algorithm.