Abstract：Carbon neutrality is a crucial strategy for combating global warming, and Negative Emissions Technologies (NETs) are key to achieving this goal. The ocean, as the largest carbon reservoir on Earth, plays an irreplaceable role in regulating the global carbon cycling and holds significant potential for negative emissions. Ocean alkalinity enhancement is regarded as a highly efficient and ecologically beneficial negative emissions technology. This technology not only increases ocean alkalinity by adding alkaline minerals to seawater, thereby enhancing the absorption of atmospheric CO2, but also improves the buffer capacity to resist the ocean acidification. This study introduces the mechanisms and advancements in ocean alkalinity enhancement research at multiple scales, based on the dissolution theory of carbonates in the ocean. Assessing the potential for negative emissions and associated costs reveals several challenges regarding implementation pathways, environmental impacts and public acceptance. Considering the specific conditions of China's coastal regions and the characteristics of ocean alkalinity enhancement technology, the study proposes the pathway integrated with wastewater treatment plant and coastal engineering. Furthermore, it presents an innovative concept on the application of ocean alkalinity enhancement and enriches the scientific understanding of blue carbon sinks.