ANSYS was used to carry out the finite element modal (FEM) analysis of the grinder bed and the first three natural frequencies and mode shapes were obtained. With the DHMA modal analysis system, the modal test of bed was carried out. The modal parameters were obtained. The results of modal analysis and modal test were compared, and it was found that corresponding to each order, the natural frequencies had no much difference and results of mode shapes are similar. This proves that the obtained results of dynamic characteristics are correct and the dynamic characteristics of the bed can meet the design requirements.