In the actual use of ultra supercritical labyrinth control valve, some structural safety problems may occur. To solve these problems, a thermal coupling analysis for the valve was made through ANSYS software. The temperature distribution and stress distribution of the valve under thermal stress and medium pressure were revealed. The stress analysis and evaluation of the valve body, disc components and seat parts with higher stress were discussed.The results show that the temperature of the inner surface of the valve directly contacted with the medium is higher, and the temperature of the valve forms a temperature gradient along the direction of the wall thickness. The temperature at the edge of the valve and on the top is low. The stress intensity evaluation results show that all the parts except the valve seat meet the specifications and have a larger margin of safety.