The process of CO₂ sequestration in deep saline aquifers involves fluid migration and pressure transmission. Based on the field data of CO₂ sequestration in saline aquifers in the Frio region of the United States, a two-dimensional multi-lithofacies model was established. The variation characteristics of the rock permeability during CO₂ injection, the variation characteristics of the rock pressure, and the evolution of the CO₂ plume were simulated and analyzed. The results show that the formation of a funnel-shaped diffusion halo was observed when supercritical CO₂ displaced the salt water, and salt precipitation due to evapotranspiration mainly occurred in the single gas phase region near the well. As salt precipitation increased, the permeability near the well decreased and the pressure increased. If the permeability of the cap rock is improved, the pressure in the reservoir will decrease, but the possibility of leakage will increase.