To realize long-term objectives of carbon peaking and neutrality in China，injecting captured CO₂ generated by fossil fuel combustion into high-water-cut reservoirs may not only enhance oil recovery，but realize CO₂ geological storage in oil layers. This is conducive to achieving the dual goals of increasing oil and gas production and reducing carbon emissions. In view of the characteristics of high-water-cut reservoirs，a comprehensive review is carried out from the aspects of CO₂ flooding and geological storage mechanisms，storage modes，storage-capacity calculation methods，CO₂ migration，and leakage-risk prediction and evaluation. Based on the research status of CO₂ flooding and geological storage in high-watercut reservoirs in China and abroad，as well as the closely related scientific fields and the problems faced by mines，this paper puts forward ten key issues needing further research，such as reaction of CO₂ with reservoir rocks and fluids，CO₂ flooding mechanism and storage mode，storage capacity，storage efficiency，and leakage-risk prevention and control. This provides a reference for research directions of CO₂ flooding and geological storage，as well as industrial technology reserves.The solution to the key issues of CO₂ flooding and geological storage is of great significance for serving“carbon emission reduction”and“carbon sink increase”to achieve the strategic goals of carbon peaking and neutrality in China.