Accurately assessing the dry deposition fluxes (DDF) of inorganic nitrogen aerosol (aerosol-IN) is crucial for mitigating the ecological damage caused by excessive nitrogen to oceanic equilibria. We developed a dry deposition model to assess the DDF of aerosol-IN into Chinese offshore areas from 2011 to 2020, ranging from 3.95×106 g/(km2 year) to 6.00×107 g/(km2 year). Our findings showed a clear decline in the DDF of aerosol-IN following the implementation of atmospheric laws and policies. Promoting the use of new energy vehicles, the rational use of nitrogenous fertilizers, and standardized straw burning will all reduce pollution caused by excessive nitrogen deposition. Aerosol-IN is a more significant source of inorganic nitrogen than river transport in Chinese offshore areas. The reduction of aerosol-IN dry deposition is a beneficial factor in mitigating offshore eutrophication, which should be considered when devising strategies for the protection and development of China's Beautiful Bay.