The experiment studied the united application of Pro/E, Ansys and Optistruct in packaging machinery design. Based on the analysis of the advantages and characteristics of Pro/E, Ansys, and Optistruct software, combining their focuses and advantages in packaging machinery design, the united application of these software in the practical research and design was put forward, and the data transfer between them was described. In the instance of the process of packaging machinery design, the united application research of the software was carried out. Pro/E, Ansys and Optistruct had their own advantages, respectively focused on drawing 3D modeling, finite element simulation analysis and structure optimization. The data can be transferred between them, the united application was achieved in packaging machinery design. The optimization example of bracket structure design showed that the maximum stress reduced by 18.4% , respectively, the maximum deformation decreased by 58%. The united application of Pro/E, Ansys and Optistruct in packaging machinery design made the design process efficient and accurate, the optimization effect was obvious.