Abstract: Compressed air energy storage in aquifer (CAESA) is a prominent technology in the process of achieving the ‘Carbon Peaking and Carbon Neutrality’ goal, the flow characteristics and geochemical processes in the reservoir are prerequisites for its large-scale application in the future. On the basis of bibliometric analysis, the development timeline of the technology and the exploration process of filed experiments are systematically summarized, the previous studies on reservoir flow conditions during compressed air energy storage are comprehensive summarized, the variation of reservoir properties is summarized with an emphasis on geochemical processes, and the corresponding research outlook is proposed. The results show that: (1) Permeability and porosity determine the system performance by influencing the stability of the pressure of reservoir bubble. There is a suitable permeability range, a lower permeability will limit the gas circulation, while a higher value is not conducive to maintaining the bubble pressure. (2) Stress variation and geochemical process can cause changes in reservoir flow parameters, the geochemical processes mainly include primary mineral dissolution, secondary mineral precipitation and oxidation reactions, among which the water-rock reactions involving CO₂ have significant impact on the reservoir. In order to achieve a breakthrough in understanding the flow characteristics of reservoir, research should be emphasized in areas related to reservoir properties and compressed air storage mechanism, and be focused on the variation of reservoir flow conditions and the influence of reservoir heterogeneity in the combination of various methods including experiment and numerical simulation. Research on the kinetics and thermodynamic behavior of compressed air in reservoir should be strengthened to clarify the key influence of geochemical processes on reservoir, and to demonstrate the high efficiency and feasibility of large-scale energy storage applications from the perspective of reservoirs.