The 750 kV structural gantry is a high and heavy load steel latticed structure,which is of vital importance in the 750 kV electric substation. It has high vulnerability during earthquakes. In this work,finite element models of 750 kV structural gantry with and without isolation layer are established by ANSYS. Dynamic time-history analysis are carried out by inputting seismic waves for these two models. The results show that by adopting suitable isolation bearing the structure gantry with base isolation has lower frequency. Apart from this,its top displacement response and pole stress have different degrees of reduction compared to those of gantry without base isolation. These conclusions indicate that it is effective to use isolation system,which has provided a basis for practical application of isolation technology in power tower.