To solve the problem that substation lateral stiffness is small and large equipment will amplify the seismic action,two methods of seismic isolation design were adopted for Suqian 220kV substation structure by divisional design and integrated design respectively,and the principles of determining the bearing parameters,rules for selecting seismic waves,floor response,and the influence laws of non-proportional damping were researched and analyzed.The results show that the bearing parameters obtained iteratively under the actual seismic action should be used,and the damping ratio of the seismic isolation layer obtained iteratively as the structural damping ratio is more reasonable for the selection of seismic waves,and the integrated design method can be used to optimise the components and improve the structural economy while realising the seismic elasticity target requirements,and the nonproportional damping characteristics of the seismic isolated structure of the substation are stronger and have a greater impact on the results of the floor response,and the influence of nonproportional damping cannot be neglected in the actual seismic isolation design.It is more appropriate to adopt the integrated design method for substations in high-intensity areas.