Abstract: In order to improve work efficiency and reduce vibration for vertical cutting table, a multi-objective optimization design based on an improved PSO algorithm for cutter drive mechanism of half-feeding combine harvester is performed in this paper. Mathematical model is established by taking the best drive performance and minimization of overall mechanism mass as two major goals. Accuracy and feasibility of the algorithm and mathematical model are verified by MATLAB-PSO toolbox. A user interface developed by VC++ software development platform can display data intuitively and make operation convenient. Calculation results show that minimum transmission angle increases by 5.49%, and mechanism size decreases by 23.07% in the same situation to meet transmission requirement. Study indicates that multi-objective optimization based on improved PSO algorithm can improve performance and reduce the size of mechanism at the same time.