The utility model provides a be applied to electric power system's integrated transformer. The utility model relates to an electric power system's integrated transformer. For the problem that the leakproofness is not good of solving the transformer. Conservator, transformer on case lid, low tension side oil tank rising base, middling pressure side oil tank rising base, high -pressure side oil tank rising base, pressure relief device, oil purifier, respirator, oil tank lateral wall, fuel outlet valve, transformer body, multiunit radiator and transformer tank bottom shell body with structure as an organic whole. Beneficial effect is good for the leakproofness of this integration transformer, and simple to operate can not arouse the oil leak because the installation method is improper yet. The device is suitable for the electric power system.