In order to improve the static and dynamic stiffness and reduce the quality of the machine bed,the finite element model of the machine bed structure was established.The static and dynamic characteristics and loworder natural frequency of the machine bed were obtained through the finite element analysis technology.On this basis,using the method of size optimization and topology optimization,the structure optimization design aiming at reducing the mass and improving the structural stiffness was carried out,and the comprehensive optimization of the bed was finally completed.Comparing the optimized bed with the original bed,the results show that the max deformation of the bed after comprehensive optimization is reduced by 19.45% and the stress is reduced by 12.24%.The natural frequencies of the first five orders are obviously improved,while the quality of the bed is reduced by 3.52%.Through comprehensive optimization,the working performance of the bed is improved and the weight of the bed is reduced.