Abstract: Regarding the five types of faults (abnormal sounds, tripping, oil leakage, abnormal increase in oil temperature, and discharge) in the cooling system of the No. 1 transformer at the 220 kV Jinzishan Substation, this article analyzed the causes and formulated a targeted technical solution. The application results show that after the fault handling, the operational stability of the equipment has improved, the heat dissipation and monitoring efficiency have been optimized, the component lifespan has been extended, the operation and maintenance intensity has been reduced, and effectively ensured the safe and stable operation of the transformer and the regional power grid.