“In the process of achieving China's "dual carbon" goals, the storage of CO2 in saline aquifers is an important approach. The southwestern region of China has abundant saline water resources and enormous potential for CO2 sequestration. Through indoor simulation of formation temperature and pressure conditions, 20 sets of CO2 water rock interaction experiments were conducted to explore in depth the evolution characteristics of carbonate rock properties and pore throat structures under CO2 action. The research results indicate that the higher the volume fraction of CO2, the more significant the changes in the physical properties and pore throat structure of carbonate rocks. Provided valuable data support for CO2 sequestration in saline aquifers.”