1MSF-3-type collector of used plastic film on farm machine is the main bearing parts of wide-folding frame. The strength and rigidity of wide-folding frame directly affects the normal operation of the residual film retrieving ma-chine. Therefore, based on using SolidWorks to establish 3D parametric model for wide-folding rack. At the same time, the model is imported into ANSYS Workbench to static characteristic analysis and to get equivalence- stress and equality-displacement cloud atlas under the working condition. According to the result of finite element analysis of wide-folding frame suggests that meets the design requirements of strength and stiffness. And then, found on the Design Explorer mod-ules of ANSYS Workbench Environment, DOE ( Design of experiment) method is used. With section size of each beam of wide-folding frame as Design variables, regarding the stress and displacement as constraints, moreover, taking its quality for an indicator, to accomplish multi-objective optimization Design for the rack. The results show that not only quality of frame is decreased by 10% after optimization but also mechanical properties are good, meanwhile, the manu-facturing cost is saved and the requirement of residual film recycling machine work is satisfied.