The invention relates to a transformer breather which comprises an upper flange, a glass cover, a silica gel, a base, an oil cup and the like. The transformer breather is characterized in that the height of the upper surface of the base is higher than that of the peripheral edge of the base, and a water retaining edge is further arranged on the upper surface of the base. Through the change on the base structure, moisture cannot flow into the breather, a breathing hole in the base can be prevented from being blocked by an ice layer, and under the conditions of humidity and low temperature, the breather can normally breathe and is ensured to play a protective function. The transformer breather is simple in structure and reliable in performance, and can be achieved by simply upgrading the traditional breather.