Abstract: Precision vertical jig boring machine is particularly demanding for machining accuracy, and the existing T-shaped bed structure has shortcomings in dynamic response and load-bearing capacity, which is difficult to meet the high standard requirements of precision machining. Therefore, a multi-objective optimization design method for the T-shaped bed considering dynamic characteristics is proposed. Firstly, finite element analysis is employed to perform static and dynamic analysis of the existing bed, obtaining the maximum deformation and the low-order natural frequencies of the bed. Secondly, a multi-objective optimization model was constructed to reduce the weight of the bed, increasing the stiffness of the guide rails, and enhancing lower-order natural frequencies. Topology optimization was then carried out. Finally, the structure of the bed was reconstructed according to the optimized topological cloud image, and the mechanical properties of the optimized bed were verified. The results show that the maximum deformation of the bed guideway in the Z-direction is reduced to 3.08 μm, a 35.0% reduction; the total mass of the bed is reduced to 9 181 kg, a 5.1% decrease, and the first three natural frequencies increase by 19.1%, 15.3%, and 13.6%, respectively. The optimized bed structure exhibits a significant improvement in mechanical performance, enhancing both its dynamic characteristics. This study provides new ideas and methods for the structural design of vertical jig boring machine and offers valuable references for the optimization of beds in other high-precision machine tools.