The invention relates to the field of charging piles, in particular to a waterproof protective cover for a charging gun of an automobile charging pile. The waterproof protective cover at least comprises a box body of a charging pile and further comprises a base frame, a protective cover body, a waterproof part, a sealing ring and an electric telescopic rod, the base frame is fixed outside the box body, a charging gun opening of the charging pile is located in the base frame, openings are formed in the two sides of the protective cover body, a notch is formed in the lower surface of the protective cover body, an opening in one side of the protective cover body is hinged to the base frame, the waterproof part is arranged in an opening in the other side of the protective cover body, the sealing ring is embedded in the base frame and makes contact with the protective cover body, and the connecting end of the electric telescopic rod is hinged to the box body. Due to the adoption of a rubber mold or waterproof canvas, the problem of special-shaped bulge of the charging gun is effectively solved, the waterproof protective cover can adapt to the shape of the charging gun, a larger waterproof cover is not needed, and the practicability of the waterproof protective cover is further improved. Due to the fact that the electric telescopic rod is adopted, the protective cover can be automatically opened and closed, operation steps of a user are reduced, and meanwhile the user can be prevented from forgetting to close the protective cover.