Two-stage hydraulic cylinder telescopic marine riser assembly structure

The utility model relates to a two-stage hydraulic cylinder telescopic marine riser assembly structure and a method, and belongs to the technical field of offshore oil drilling. The two-stage hydraulic cylinder telescopic marine riser assembly structure comprises an inner cylinder, a middle cylinder and an outer cylinder, outer bosses are arranged on the outer walls of the upper ends and the lower ends of the inner cylinder and the middle cylinder respectively, inner steps matched with the outer bosses are arranged on the inner wall of the upper end of the outer cylinder, the inner cylinder is installed in the middle cylinder, and the middle cylinder is installed in the outer cylinder. The upper end of the inner cylinder and the lower end of the outer cylinder are respectively provided with a double-flange joint and a crossover flange. The up-and-down telescopic hydraulic cylinder assembly is formed by superposing the up-and-down movement strokes of the two-stage stroke hydraulic cylinders with the three over