In recent years

composite pillar insulation equipment has been used gradually in ultra high-voltage (UHV) substations. However

its elastic modulus is smaller than that of ceramic equipment

which makes the rigidity of equipment more low and system more flexible. For studying the seismic performance of its coupling system and the influence on such factors as seismic intensity

the structural dynamic response analysis theory is introduced firstly in this paper. Then

the Abaqus software is used to set up a ±800 kV composite double-pillar insulator equipment system with a tubular-bus coupling

one end of the system is fixed and the other end is sliding. After that

the modal vibration shapes of the system in different directions are analyzed and compared

the dynamic response analysis is per-formed based on the established simulation model and the influence of seismic intensity

spectrum and multi-dimensional seismic coupling on the seismic response of the coupling system is considered respectively. The results show that the first three in-plane frequencies of the coupling system are higher than the corresponding out-of-plane frequencies. When the seismic amplitude is in the range of 0.4g

the root of the insulator strains

the top acceleration and displacement response of the insulator are approximately linearly related to the seismic amplitude. The tubular busbar coupling effect

either for the fixed connection or for sliding connection

can maintain its reduction effect on the top displacement and can reduce the bottom stress level. Under multi-dimensional seismic input

the acceleration in the original direction increases with the increase of the seismic dimension. The displacement response of the coupling composite pillar insulator is large under seismic at 0.4g

and the ratio of displacement to the height of insulator height is up to 1/31

but the root strain level is low and is still at the linear elastic stage.