Rail are mostly formed by short rails to be welded up. In order to ensure the safety of high-speed train, rail welding must be strictly polished to form seamless rail, thus to ensure rail’s welding quality is crucial. At present, the domestic rail grinding machine mainly relys on manual operation and experience of workers, the grinding quality is poor, the efficiency is low and the labor intensity is large.A kind of automatic rail welding seam profile grinding machine was introduced which could be use to realize accurate profiling grinding of rail welded joint, and to conduct the fat edges polished and trimmed burrs and other works. It has the advantages of simple structure, simple operation. The production efficiency is improved, and the labor intensity is reduced based on the ensurence of rail surface’s grinding quality.