In this paper

the compact layout scheme of HGIS distribution device for Huatugou East 330 kV switching station is taken as an example and the analytical formula for calculating the electromagnetic induction voltage of bus-bar is obtained by the use of variable separation method under the condition of only considering the influence of earth.The influence of equipment（bus girder

frame column and grounding grid）and the earth on the electromagnetic induction voltage of bus-bar is analyzed in detail by the finite element method.It is shown by the result of numerical analysis that the influence of earth

bus girder and frame column on the electromagnetic induction voltage of busbar is bigger

while the influence of grounding grid can be neglected.The eddy currents in the earth

bus girder and frame column can reduce the electromagnetic induction voltage of bus-bar

while the magnetic convergence of bus girder and frame column can increase the electromagnetic induction voltage of busbar.Compared with the situation without considering the influence of equipment and the earth

the influence of the earth and the equipment around the busbar of switching station make the electromagnetic induction voltage of bus-bar increase by about 6%.In addition

when the relative permeability of material of bus girder and of frame column increases by one time

the electromagnetic induction voltage of the busbar increases by about 2%.When the conductivity of material of bus girder and frame column increases by an order of magnitude

the variation of the electromagnetic induction voltage of bus-bar is about 2%.These study results can provide theoretical basis for the design of bus grounding switch of switching stations and for assurance of the safety of busbar in maintenance.