A waterproof communication cable connection box includes a protective cover, a cable pass-through end surface, a hollow cylindrical pipe formed on the cable pass-through end surface, an elastic rubber shrinking pipe, and a flexible hard plastic strip provided on the inner wall of the elastic rubber shrinking pipe. The plastic strip will be removed after a cable passes through the cable connection box so that the elastic rubber shrinking pipe closely covers the hollow cylindrical pipe and the cable part exposing outside of the hollow cylindrical pipe.