In order to enhance the actual effect of vibration aging on large lathe bed and optimize it, many technological parameters of vibration aging will be discussed in this paper, including exciting force, exciting frequency and exciting point, etc. Finite element method is used to analyze the casting stress distribution and natural mode of vibration of a large lathe bed. After the analysis, it is found that the distribution of the residual stress of the lathe bed is extremely uneven. By analyzing parameters of the natural vibration model and the exciting force as well as the exciting point, a reasonable parameter will be got when the lathe bed is vibrating. The “Selecting low-frequency to avoid torsion mode” which reduces the deformation to bed caused by the residual stress, was proposed. The parameters have been proved effective through experiment, and the proposed approach can be used in the research of vibratory stress relief.