The utility model relates to a water cover especially relates to a rain-proof cover of transformer temperature plug-in components, belongs to the electric power installation field. Sit on annular base including the cylinder cover body, the inside and outside astragal of said annular base is fluted, inlays the sealing washer in the recess, with annular base cover on transformer temperature plug-in components interface, sealed by the sealing washer of inner circle, insert transformer temperature plug-in components interface with transformer temperature plug-in components again, fixed with fixation nut, provide the wire hole on the side upper portion of the buckler cover body, draw transformer temperature plug-in components lead wire from the wire hole of the cover body of buckler, detain the buckler cover body on annular base, sealed by inlaying at the sealing washer of annular base outer lane. The utility model provides a transformer oil bathe a section of thick bamboo and temperature plug-in components freezing problem easily, improved the reliability of transformer.