Light tube protective cap with locating end

The invention relates to a light tube protective cap with a locating end, which is used for protecting end parts of petroleum sleeves and various pipes. The light tube protective cap comprises a cap body, wherein the cap body comprises an upper section, a middle section and a lower section and is retracted in sections, an annular blade is arranged on the outer wall of the cap body, the upper section of the cap body is provided with a cap top, and the cap top and the upper section of the cap body form the locating end together. The end part of the cap top overturns outwards, and a transition platform is arranged between the cap top and the upper section of the cap body. The width of the transition platform is as same as the thickness of a pipe to be protected, and the upper section of the cap body is as same as the inner diameter of the pipe to be protected. The invention has the advantages that the cap top and the upper section of the cap body are located due to a special design of the end part of the protective cap so that the cap top and a pipe end groove are matched perfectly.