To investigate the effects of vermicompost application on organic carbon pool and its stability in coastal saline-alkaline soil, a field experiment was conducted in such soil under barley-maize rotation in Fangling Reclamation Area, Bencha Town of Rudong County, Jiangsu Province, and the vermicompost was one-time applied to the field with the rates of 0, 25, 50, 100, 200 t/hm² in October 2019, soil samples were collected in October 2022 from the topsoil layer (0-20 cm) to determine the contents of dissolved organic carbon, calcium associated organic carbon, labile organic carbon, particulate organic carbon and mineral-associated organic carbon. The carbon pool management index was calculated, and the functional group structure of soil organic carbon was analyzed by solid-state nuclear magnetic resonance spectroscopy. The results showed that compared with no application of vermicompost, soil organic carbon pool changed significantly after application of more than 50 t/hm² vermicompost, soil organic carbon content increased by 35%-97%, dissolved organic carbon content increased by 27%-104%, calcium associated organic carbon content increased by 19%-26%, and labile organic carbon content increased by 6%-94%, prticulate organic carbon and mineral-associated organic carbon increased by 14%-124% and 37%-85% respectively, and soil carbon pool management index increased by 6%-92%; The ratio of Aliphatic C to Aromatic C decreas-ed, and the values of Alkyl C/O-alkyl C and Hydrophobic C/Hydrophilic C all increased, indicating the improvement in the structural stability of soil organic carbon. In conclusion, the application of vermicompost has a significant effect on the improvement of soil organic carbon pool and its stability in coastal saline-alkaline soil, and the effect is the best under the application amount of 50 and 100 t/hm².