Abstract:All countries in the world are paying attention to low-carbon and carbon neutrality to achieve the mitigation of climate warming by reducing CO₂ emissions. Ocean is the largest carbon pool on the earth and play an important role of carbon neutrality. More than half of the biological carbon on the earth is achieved by marine organisms. Among them, seaweed resources are abundant, with advantages such as low cost, high yield, measurable carbon sink, and strong cultivation controllability. Industrialized blue carbon can be formed offshore, which is a sustainable model for future development in coastal ecosystems. In addition, large-scale cultivation of seaweed can provide potential solutions to the global marine environmental problems such as ocean acidification, hypoxia, eutrophication, and harmful algal blooms. This review focuses on the function of seaweed carbon sinks, and seaweeds' potential to solve coastal environmental problems in terms of cultivation, environmental bioremediation effects, and comprehensive benefit assessment. In conclusion, large-scale seaweed cultivation is an effective approach for developing low-carbon economy, increasing marine carbon sink capability, solving marine environmental problems, and finally achieving carbon neutrality.