The invention relates to a rail convex-concave end surface connecting device for a railway line, which belongs to the technical field of high speed railway rail. The rail convex-concave end surface connecting device for the railway line comprises a front rail, a connecting plate, a nut, a rear rail and a screw rod in the traditional device and is characterized in that the front ends of the front rail and the rear rail are provided with groove end surfaces; the rear ends of the front rail and the rear rail are provided with boss end surfaces; through holes are respectively formed in the side surfaces in the two ends of the front rail and the rear rail; the connecting plate is a long strip-shaped steel plate; through holes are respectively formed in the side surfaces in the two ends of the long strip-shaped steel plate; and the device is formed in such a way that a boss at the rear end of the front rail is mounted into a groove at the front end of the rear rail, the connecting plate is buckled at the connecting part of the front rail and the rear rail, and the front rail, the rear rail and the connecting plate are tightened together through screw rods and nuts. When train wheels pass through rail connecting parts, cracking vibration sounds cannot be generated so that passengers in train carriages can feel comfortable.