[Objective] Excessive carbon dioxide (CO2) emissions have caused global climate variability, leading to a series of environmental problems. As a key technology to reduce CO2 emissions, carbon capture, utilization, and storage (CCUS) plays an important role in relieving large-scale CO2 emission reductions, and the application of CO2 storage projects for the saline aquifer in offshore China has a broad application prospect and great technical and economic potential. [Methods] To address the problem of unclear understanding of the favorable areas and storage potential of CO2 in the saline aquifers in the Ying-Qiong Basin, the suitability evaluation of geological storage of CO2 is carried out by calculating the weights of the indicator components and the suitability score based on the geological characteristics of the Ying-Qiong Basin. In addition, the CO2 storage potential of the saline aquifer in the Ying-Qiong Basin is preliminarily evaluated by combining the effective CO2 storage coefficients calculated by the numerical simulation method and different storage potential calculation methods. [Results] Results show that the storage capacity obtained from EC method is less than that determined by the USDOE and CSLF methods. Since both of the CSLF methods consider the storage mechanisms such as geological structure storage, residual gas storage, and dissolution storage, the results seem more reasonable. [Conclusion] In summary, the CO2 storage potentials of the saline aquifer in the Yinggehai Basin and Qiongdongnan Basin are 7.96×106 and 4.40×106 million tons, respectively, and the total CO2 storage potential in the saline aquifer in the Ying-Qiong Basin is 1.24×107 million tons, which further verifies the great potential of the industrial-scale pilot and demonstration projects of CO2 storage in the saline aquifer of the Ying-Qiong Basin and provides a good opportunity for the next step of carrying out the CO2 storage project in the saline aquifer of the Ying-Qiong Basin.