Spindle box is an important part of the vertical machining center, and its static and dynamic characteristics have an important influence on the machining accuracy and smoothness of the machining center. A certain type vertical machining center spindle box was taken as the research object, SolidWorks was used to establish the 3D model of the spindle box, and ANSYS Workbench software was used to analyze the static and dynamic characteristics under typical working conditions. According to the static and dynamic characteristics analysis results of the spindle box,the structure of the spindle box could be optimized.The topology optimization module of ANSYS Workbench was used to optimize the spindle box structure.According to the topology optimization results and the actual working conditions, the spindle box structure was reasonably improved.The analysis results before and after improvement show that the improved spindle box mass is reduced by 2.3%,the maximum equivalent stress is reduced by 3.34%,and the static stiffness is improved,so the optimization purpose is achieved. The research results provide reference for the optimization design of other types of machine spindle box