Abstract: The simplified finite element model of the machine tool bed was established with ANSYS and the natural frequency was detected as the index of the dynamic performance. Based on the simulation analysis, the first 6-order natural frequency and vibration modes were comparatively analyzed, during which the effect of the bed height on the its natural frequency was studied. The impact of the arrangement mode of ribbed plate of the spindle box supporting platform on the bed dynamic properties was also investigated and some effective solutions were proposed. It indicates that an optimized machine tool has better dynamic performance, which can offer higher workpiece quality and process stability.