Power transformer

The invention relates to the technical field of transformers, and provides a power transformer which comprises a transformer body, a shell mechanism, a driving mechanism, a lifting mechanism, a rotary drum and an air pump, a middle cavity is formed in a protective shell in the shell mechanism, and the rotary drum is movably arranged in the middle cavity in a sleeved mode; a plurality of first ventilation parts and a plurality of second ventilation parts are arranged on the surfaces of the protective shell and the rotary drum respectively, tooth grooves are formed in the surface of the rotary drum, a transmission gear in the lifting mechanism is installed at the lower end of a threaded rod, a lifting plate is in threaded connection to the surface of the threaded rod, and a transformer body is installed on the surface of the lifting plate. A cavity is formed in the lifting plate, first ventilation holes are formed in the upper side and the lower side of the lifting plate correspondingly, the air pump is install