In order to reducing the weight of base while meeting the using requirements, the topological optimization of the design of the structure is done by 3D design software Pro/E and ANSYS Workbench. According to the advantages of topological optimization, studying on the base of some kind of position stage, establishing the 3D model with Pro/E, the topological optimization of the base is done under the real working condition with ANSYS Workbench which has the powerful function of finite element analysis. Comparing the static characteristics and dynamic characteristics of the base in the topological optimization after and before, the results of analysis shows that: the stiffness and nature frequency of the optimized base are all effectively improved, while reducing the quality with 10%, and these proves that the design with topological optimization has a good significance in theory for the productive practice.