Abstract: As the component of electric power system, High??voltage electrical equipments have some traits such as heavy weight, small damp ratio and poor distortion of accessorial parts, which lead to weak aseismatic ability. High??voltage reactors were destroyed badly in 5??12 Wenchuan earthquake, which caused blackout in earthquake reg ion and brought so many difficulties for rebuilding. It is studied the application of isolation technology in high??voltage reactors in a real substation. The isolation layer made of laminated rubber bearing is set under reactors layer. A new type model of simulating high??voltage electrical equipments has been built up successfully to solve the problem of difficult modeling . It is also presented calculation method and analytic steps in a real isolated electric project and compared to the results of non??isolated one. The results show that isolation technology can decrease the seismic reaction of reactors obviously and it's the effective way to enhance aseismatic ability of high??voltage electrical equipments.