The invention discloses a sealing tensile cylinder which comprises a sealing cylinder and a tensile cylinder, wherein the sealing cylinder comprises a shared end cover, a front end cover, a sealing cylinder barrel for connecting the shared end cover and the front end cover and a sealing piston rod which is embedded into the shared end cover and penetrates through the front end cover; a sealing piston which is sleeved on the sealing piston rod is also arranged in the cylinder barrel; and the sealing piston rod is a hollow concentric double-shaft piston rod, and the shaft head end of the concentric double-shaft piston rod is provided with a dual seal ring. The sealing piston rod is changed from a single shaft to double shafts, the guide sleeve length of the piston rod is increased, the action of the piston rod is more stable, and the radial jump of the piston rod is reduced. The gas consumption of the sealing cylinder is reduced, and the action speed of the cylinder is higher. The shafthead end of the double-shaft piston rod of the sealing cylinder is provided with the dual seal ring which can replace a sealing head of the common sealing tensile cylinder, i.e. the sealing head is not installed, thereby the cost of products is reduced.