Abstract: Abstract: In order to study the effect of the transient thermal shock on the structural strength and fatigue life of the nuclear secondary bellows globe valve, the hot-fluid-solid coupling analysis of the nuclear secondary globe valve body was carried out by Fluent and ANSYS software, based on the theory of fluid-solid coupling and thermal boundary condition. The effects of the temperature field, thermal stress and fatigue life of the monitoring point at different time points and the effect of the thermal shock time on the fatigue life of the degree of sensitivity were studied. The results showed that the effects of the transient pressure on the temperature field, structural strength, fatigue life and sensitivity of the valve body was huge, and have to be eliminated to ensure the high safety of the nuclear secondary bellows globe valve.