Abstract: Driven by the “dual-carbon” goals, carbon capture, utilization, and storage（CCUS） technology has been recognized as a key means for carbon emission reduction. Coastal provinces and cities in China are characterized by concentrated industries and huge carbon dioxide emissions. Additionally, offshore areas offer vast space and high safety for carbon storage. Therefore, the offshore carbon storage model has gradually emerged as an important option for coastal regions to achieve the “dual-carbon” goals. As a core component of offshore carbon storage, the optimization of source-sink matching directly determines emission reduction efficiency and economic costs, and is of great significance for achieving economical and efficient emission reduction. This study focuses on the issue of offshore carbon storage source-sink matching between the coastal areas of Jiangsu and Shandong Provinces and the South Yellow Sea Basin. Based on the China high-resolution emission grid database（CHRED）, carbon emission data from industries such as iron and steel, chemical, cement, and thermal power in the coastal areas of Jiangsu and Shandong Provinces are selected. The minimum spanning tree algorithm is introduced, and an offshore carbon storage source-sink matching model is constructed. A study on offshore carbon storage source-sink matching in the coastal areas of Jiangsu and Shandong Provinces is conducted, the total cost of the source-sink matching system is calculated, the optimal pipeline transportation routes are proposed, and the optimal source-sink matching pattern is developed. The study shows that the favorable carbon storage zones in the Yantai Depression and Qingdao Depression of the South Yellow Sea Basin exhibit good matching characteristics with the carbon emission sources in the coastal areas of Jiangsu and Shandong Provinces, which can meet the demand for carbon emission reduction in the next 30 years and provide a geological basis for offshore carbon storage. The unit transportation cost of the proposed source-sink matching pattern is 0.015 6 USD/t/km. With the impact of technological innovation and rising carbon prices, the economic benefits of the offshore carbon storage development path under the proposed source-sink matching pattern will be more optimistic. This study provides a scientific decision-making basis for coastal provinces and cities to build a land-sea integrated emission reduction system under the “dual-carbon” goals, and helps promote the large-scale application of the technical pathway of “onshore carbon to offshore storage”.