The utility model discloses a totally closed power transformer mainly relates to transformer technical field. Including transformer housing, establish transformer ware body in the transformer housing, transformer oil, transformer housing establishes at the top transformer apron, establish the screw hole on the transformer apron, threaded hole establishes the oil level gaugember body, the internal thread is established to the lower extreme to the oil level gaugember body, establish the oil level gaugember disk cover on the oil level gaugember body, the supporting seat is established at the transformer apron end, the fluid ascending pipe is placed in the oil level gaugember body, establish hollow oil baffle disc at the bottom of the fluid ascending pipe, establish the support piece in the fluid ascending pipe, the support piece rotates connects the oil baffle, establish the fixed block on the fluid ascending pipe inner wall, the top end opening female connection of the department stopcock of fluid ascending pipe, thread connection ascending pipe disk cover. Beneficial effect: can be convenient observe oil level, the oil colours in the transformer, sealed effect is better, and does not need to set up in addition the oiling mouth, the convenient transformer oil that supplyes, the noise reduction is dispersed to improve equipment life reduces the maintenance cost.