A tail sleeve structure of a network signal connector includes a main body and a pair of propping structures. The main body has a penetrating passage in the middle, a pair of rails symmetrically installed on the inner wall surface of the penetrating passage, an opening formed at the diagonal positions of the end surface of the pair of rails respectively, and two mounting holes formed at the other diagonal positions respectively. Each propping structure includes a propping pillar and an elastic element movably installed into the mounting hole.