Abstract: Because primary transformers in substation will be wrecked badly in earthquake disaster and are hard to repair, so it is necessary to improve the ability of its antishock. Based on the damage investigation of primary transformer during wenchuan earthquake disaster, isolation and energy dissipation technologies are applied to body and basic design of primary transformer after analytic demonstration. Through prolonging basic vibration periods, this technique can improve damping ratio, realize the isolation of energy input in earthquake and reduce influence of earthquake. It is verified that this technique has its advantage by comparing with traditional antishock and reinforce measures. In the end, two design schemes are presented as reference to substation reinforcing or building.