Abstract: The end of the riser pipe clamp of a high-temperature reheat steam pipe in a power plant was deformed. The reasons for the deformation of pipe clamp were analyzed through geometric measurement, chemical composition analysis, tensile test, and thermal-structure coupled finite element analysis. The results showed that there was a stress concentration phenomenon in pipe clamp at the corners of the straight section and the curved section, and the equivalent stress exceeded the yield strength of the material at corresponding temperature, resulting in deformation of pipe clamp. By increasing the thickness of pipe clamp and setting ribs at the corners of the straight section and the curved section, the maximum equivalent stress could be reduced below yield strength of the material at corresponding temperature, effectively preventing deformation of pipe clamp.