Under the background of "two-carbon”, carbon capture, utilization and storage（CCUS） technology will play a key role．In order to solve the problem of low temperature in CO₂ -EOR well on packer and seal aging, a theoretical model of CO₂ temperature distribution in injection well was first established. Then, a numerical simulation model of the sealing ring was established by finite element method, and the equivalent stress, contact pressure and real strain of the rubber sealing ring at different temperatures were studied, and the influence of low temperature on the mechanical properties of the sealing ring and the causes of low temperature aging were analyzed. The results show that the sealing operating temperature of the packer in the CO₂ injection well is above its glass transition temperature T_g, and low temperature aging will not occur during normal operation. Mises stress and contact pressure increases 3 ~4 times compared with that at normal temperature, the mechanical properties of injection pipe valve seals are significantly affected at low temperature. When the ambient temperature is lower than T_g, the sealing ring will change from a high elastic state to a glass state, and its hardness will increase, elasticity will decrease, and the aging degree will gradually deepen, resulting in the failure of the sealing ring when the contact pressure is less than the medium pressure.