In high-intensity areas, when power facilities must be placed on more than two floors of the structure, the traditional seismic design makes it difficult to meet the requirements of considering the dynamic amplification factor of more than 2.0 in the code. The existing equipment isolation code design does not fully consider the dynamic coupling between equipment and structure. Therefore, this paper proposes an analysis process of seismic isolation technology for GIS equipment upstairs considering the coupling effect of equipment and structure in high-intensity areas to improve the seismic safety performance of equipment. Firstly, the equivalent equipment steel frame model is established, and the isolation effect of the single equipment and the structure-equipment coupling model is evaluated in the time domain. Then, the influence of isolation effect evaluation and coupling effect on the seismic response of the equipment is studied in the frequency domain. The results show that the equivalent calculation model of the designed equipment steel frame can approximately reflect the seismic response of the equipment. After the isolation design, the equipment's deformation is concentrated in the isolation layer. After the isolation of the equipment, it tends to be a rigid body translational motion state under the action of an earthquake. Under the 8-degree fortification earthquake, the minimum isolation effect of the acceleration and base shear of the single equipment model and the equipment coupling model exceeds 50%. The sensitive vibration frequency band of the original equipment is wide and the peak value is high. After the equipment is isolated, the vibration frequency band becomes narrow and the peak value decreases. The predominant period corresponding to the peak acceleration response spectrum of the equipment after isolation is prolonged, and the response spectrum value is reduced. In the acceleration time history, the coupling effect between the equipment and the building in the x direction amplifies the seismic response of the equipment, while the coupling effect in the y direction reduces the seismic response of the equipment; in the spectrum, there are two peak intervals in the acceleration spectrum of the single equipment and the coupling equipment. The former peak interval is the resonance interval of the equipment itself, and the latter peak interval is the resonance interval of the structure. The two resonance intervals of the coupling equipment are more obvious than the resonance interval of the single model, and the interaction between the equipment and the building structure is significant. In the response spectrum, the response spectrum of the coupled equipment is relatively stable, the value is low, the change is gentle, and the difference between the two resonance peaks is small. The response spectrum peak of the single equipment model is higher and the peak value changes greatly. The difference between the two resonance peaks is large. The coupling between the equipment and the structure helps to reduce the seismic response of the equipment.