The invention discloses a method for fast dismounting and mounting railway sleepers, which relates to the technical field of railway sleeper dismounting and mounting. The railway sleeper comprises an inner railway sleeper and an outer railway sleeper, wherein both ends of the inner railway sleeper are respectively and fixedly provided with an outer clamp used for clamping the bottom edge of the inner side of a rail, both ends of the outer railway sleeper are respectively and fixedly provided with an inner clamp used for clamping the bottom edge of the outer side edge of the rail, the distance between the two outer clamps is determined through the distance between the bottom edges of the inner side of the rail, and the distance between the two inner clamps is determined according to the distance between the bottom edges of the outer side of the rail. The method has the advantages that the mounting and the dismounting of the rail are convenient, the carrying and the transportation are convenient, and the repeated utilization rate is high.