The invention relates to the field of safety protection of rail transportation, and in particular to a straddle type single-rail combined train bumper. The straddle type single-rail combined train bumper comprises a fixed train bumper and a slidable train bumper, wherein the fixed train bumper and the slidable train bumper are respectively arranged on a prefabricated line terminal PC (prestressed concrete) beam, and the slidable train bumper is arranged at the part with setting distance in front of the fixed train bumper; the slidable train bumper is in friction type sliding connection with the surface of the PC beam; the slidable train bumper is provided with a first impact part, a friction part and a first buffer structure; the fixed train bumper is provided with a fixed structure and a second buffer structure. The straddle type single-rail combined train bumper has the advantages that by adopting the structure, the fixed train bumper and the slidable train bumper are respectively arranged on the PC beam which is prefabricated as the line terminal, a train impacts the slidable train bumper, the slidable train bumper slides and rubs to consume the impact kinetic energy, the other impact kinetic energy is consumed by a hydraulic and pneumatic buffer of the slidable train bumper, and a large amount of the impact kinetic energy of the train is consumed; the backward moving slidable train bumper impacts the fixed train bumper, the remained impact kinetic energy is consumed by a hydraulic and pneumatic buffer of the fixed train bumper, and finally, the braking function is realized.