To investigate the effect of vermicompost application on organic carbon pool and its stability in coastal saline-alkaline soil. A field experiment was conducted in the coastal saline-alkaline soil with barley-maize rotation in Fangling Reclamation Area, Ben cha Town of Ru dong County, Jiangsu Province, and the vermicompost was one-time applied to the field with the rates of: 0 (VC0), 25 (VC25), 50 (VC50), 100 (VC100), 200 (VC200) t/ha in October 2019. In October 2022, soil samples from the topsoil layer (0 - 20 cm) were collected 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 show that: compared with no application of vermicompost, soil organic carbon pool changes significantly after application of more than 50 t/ha vermicompost, SOC content increases by 35 %-97 %, dissolved organic carbon content increases by 27 %-104 %, calcium associated organic carbon content increases by 19 %-26 %, and labile organic carbon content increases by 6 %-94 %. Particulate organic carbon and mineral-associated organic carbon increases by 14 %-124 % and 37 %-85 % respectively, and the soil carbon pool management index increased by 6 %-92 %; The ratio of Aliphatic C to Aromatic C decreased, and the values of Alkyl C/O-alkyl C and Hydrophobic C/Hydrophilic C increased, indicating that the structural stability of soil organic carbon was improved. 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/ha.