Co2 miscible flooding is an advanced enhanced oil recovery (EOR) technique predicated on injecting carbon dioxide into hydrocarbon reservoirs under conditions that achieve miscibility with the crude oil, fundamentally altering fluid properties to facilitate more efficient displacement. As an academic concept and research field, it investigates the complex phase behavior, dynamic flow mechanisms at multiple scales, and the impact of reservoir heterogeneity on achieving and maintaining miscibility, aiming to optimize oil recovery efficiency and explore synergies with carbon sequestration objectives. Its significance lies in providing a highly effective method for mobilizing otherwise unrecoverable oil resources while potentially contributing to greenhouse gas mitigation.