Abstract: In order to obtain the reasonable structure and support mode of the grinding wheel rod with a large length-diameter ratio and ensure that the grinding wheel rod meets the stiffness requirements, the static deformation and constraint mode of the grinding wheel rod were analyzed via Finite element method by establishing a three-dimensional parametric model of the grinding wheel rod for large depth-diameter ratio hole, and the second-order response surface model of each design variable and optimization goal of the grinding wheel rod were constructed via optimal space-filling design method. The NSGA-II algorithm was used to optimize the grinding wheel rod with multiple objectives. After lightweight optimization design and simulation comparison, a rationalized structure of grinding wheel rod and support with large length-diameter ratio was obtained, and the lightweight rate reaches to 10.3%. The analysis results show that the quality, stiffness and mode of the grinding wheel rod all meet the engineering requirements.