Abstract: Based on the temperature field simulation and sealing performance analysis of the double-cone seal structure, the change of temperature distributions and contact stress of sealing surface along with time were systematically studied. The results indicated that the temperature impact caused by the radical change of temperature was the main reason for the leakage of the double-cone seal structure. To improve the adaptability of the seal structure to temperature changes, a thermal shock technology of the double-cone seal structure is proposed, i.e., a simple and easy-to-installation heat-shock shield is applied to the double-cone seal structure to improve its capacity of resisting the thermal shock. The analysis showed that, this technology can effectively decrease the thermal shock effects on the sealing surface, greatly restrain the decreasing trend of the contact stress, and improve the reliability of the double-cone seal structure.