Remanence is the result of hysteresis loss in the process of transformer core magnetization. When the transformer core is affected by remanence, it becomes a necessary work to eliminate remanence. At present, it is a better method to add an AC magnetic potential to eliminate remanence. But there are also control problems. Hysteresis loss is a kind of energy loss, The magnetization process of the iron core is the orderly arrangement of the small magnetic poles in the iron core material under the action of the external magnetic potential. Therefore, according to the mechanism of remanence formation, we can take measures to eliminate the remanence and add a reverse DC magnetic potential for demagnetization, which is difficult to control, but theoretically, it is possible to increase the environmental temperature of the iron core, accelerate the molecular thermal movement of the iron core material, and make the iron core more stable The orderly arrangement of magnetic poles is disordered again.