As the most effective and potential carbon capture，utilization，and storage（CCUS）technology，Carbon dioxide capture，EOR-utilization and storage（CCUS-EOR）is one of the important means to realize carbon peaking and carbon neutrality goals. However，its development and application are restricted by economical efficiency at present. To explore the actual economic effect of CCUS-EOR projects and its improvement methods，this paper conducted the economic evaluation of four typical projects in China and probed into the key economic factors influencing its economical efficiency via the comparative analysis of key parameters and sensitivity analysis. Then，the benchmark balance boundary of key economic parameters was calculated by the benchmark balance analysis technology. The results show that the international oil price of about 70 US dollars/barrel is needed for the internal rate of return of most projects to reach the standard when the CO₂ price is 300 yuan/ton. The economic effect of CCUS-EOR projects is mainly influenced by the oil price，oil production increment，CO₂ price，oil draining ratio，and construction investment. In a bid to ensure that the projects’rate of return can reach the standard，the CO₂ price should be less than 300 yuan/ton，the oil draining ratio smaller than 4.5 tCO₂/toil，and the construction investment less than 700 yuan/ton. The lower these are，the projects’internal rate of return is higher. The paper also discussed three ways of carbon trading benefits，financial support and tax incentives，and simultaneous storage of multiple reservoirs to improve the economic effect of the projects from the outside in hope of providing reference for CCUS-EOR technology development planning and project implementation.