The invention discloses a power transformer for a power distribution network substation. The power transformer comprises a transformer body, wherein a high-voltage bushing and a low-voltage bushing are arranged at the top of the transformer body, two fixing frames are fixedly connected to the side wall, close to the top, of the transformer body, and the tops of the two fixing frames are connected with the same oil conservator; a first connecting pipe is connected between the oil conservator and the transformer body, a gas relay is arranged on the first connecting pipe, a fourth connecting pipe is arranged at the top of the oil conservator, a rubber bag is connected to the end, located in the oil conservator, of the fourth connecting pipe, and a second connecting pipe is connected to the end, located outside the oil conservator, of the fourth connecting pipe; the other end of the second connecting pipe is connected with a moisture absorber, and a cooling mechanism is connected between the two fixing frames. The power transformer is advantaged in that good and efficient cooling and heat dissipation can be achieved, meanwhile, filtering and impurity removal can be conducted on transformer oil, the service life of the transformer oil is prolonged, and stable operation of a transformer is guaranteed.