The pedestal design of steam turbine is one of the key works in the structural design of power plant. In the pedestal design process for one 660 MW steam turbine in China, the comparative analysis was investigated by building the solid finite element model with Ansys and the discrete model with Sap 2000, in order to ensure design quality. This paper presented the suitable structure of the pedestal with good dynamic characteristics for this steam turbine, which could be a reference for the design of similar units.