Abstract: The thermal shrinkage tube of the third-generation PWR nuclear power plant was irradiated by beta ray and gamma ray at 9 different doses. The mechanical properties of thermal shrinkage tube were measured. In the process of radiation aging test,crack elongation is used as the parameter to evaluate the damage of heat-shrinkable tube after radiation irradiation. When the elongation at break of thermal-shrinkable tube is the same after a given dose of beta radiation as it is after another dose of gamma radiation,the two doses are considered to be equivalent. According to the test results,the curve fitting of elongation at break with the change of radiation dose is carried out,and the equivalent proportional relations of heat-shrinkable casing under two different types of radiation irradiation are obtained. It provides a reference for the research and development of the 1E class in containment heat shrinkable tube of the thirdgeneration PWR nuclear power plant and the test conditions of quality evaluation.