Whole-indoor substation is a key node of power system. Its equipment arranged on the building floor is very important for the safety operation of substation under earthquake action. In this paper

finite element models of four substation buildings and their floor electrical equipment are established firstly. Dynamic characteristics and seismic response of the models under 100 ground motions are analyzed.The floor response spectrum is obtained from the responses using mathematical statistics and linear fitting. The results show that the mean vales of the peak acceleration amplification factor for the second floor and the roof of the integrative building structure is 1.35 and 2.47

respectively. When the ratio of the fundamental period of the floor electrical equipment to the integrative building structure is between 0.9 and 1.1

the amplification factor of the mean floor response spectrum reaches the peak 4.80. The design floor response spectrum is related to four factors

including the importance category

floor location

damping ratio

and the torsion effects of integrative building. It is suggested to adopt the floor response spectrum design method recommended in this paper for anti-seismic design of the floor electrical equipment in the whole-indoor substation.