Self-inflating sealing ring, cylinder section clamping tool and inner wall protection and local oxidation method

The invention relates to a self-inflating sealing ring, a cylinder section clamping tool and an inner wall protection and local oxidation method, and belongs to the technical field of aerospace large cylinder section structures. The problems that in the prior art, a large cylinder section uses a conventional sealing ring or a large rubber plug and is very difficult to install or cannot be disassembled after being oxidized, a large-size cavity is formed in the large-size cylinder section, and normal oxidation cannot be achieved are solved. The self-inflating sealing ring comprises a sealing ring shell and filler, and the sealing ring shell is provided with a feeding port; the sealing ring shell is filled with the filler, the filler is a chemical reactant which generates gas through a chemical reaction, and the generated gas achieves inflation and expansion of the sealing ring shell; and the gas is one or more of carbon dioxide and oxygen. Local oxidation under the protection of the inner wall of the aerospace