Carbon Capture, Utilization, and Storage (CCUS) technology has emerged as the bottom-line technology for achieving carbon neutrality goals in China. The development of Carbon Dioxide Enhanced Oil Recovery (CO₂-EOR) not only increases revenue for high-investment CCUS projects but also enables permanent CO₂storage in the oil reservoir. However, the basin is used as the research object to evaluate the CO₂storage potential of the oil reservoir. The evaluation results are inaccurate and unable to support the implementation of later CCUS projects. Here, more accurate oil reservoir data is employed as the evaluation object. It is the first time at the national level to screen oil reservoirs to distinguish between CO₂miscible and immiscible, and evaluate the potential of CO₂-EOR and CO₂storage in the reservoir. The research results show a total of 2570 suitable oil reservoirs in 4386 candidate oil reservoirs nationwide. About 1.26 billion tons of additional crude oil can be produced by CO₂-EOR technology. This includes approximately 580 million tons of additional oil from CO₂miscible flooding and 680 million tons from CO₂immiscible flooding. The study further refines the CO₂geological utilization data and provides a theoretical basis for CCUS project site selection in China.