Abstract: Remote sensing satellites enable an efficient and extensive monitoring of the occurrence and development of marine green tides, while the accurate identification and extraction of green tides are significantly important for the protection of the marine ecological environment. The present study proposed a green tide information extraction method with the combinations of the multi-band ratio method and RF algorithm. Based on the high-resolution Sentinel-2 imagery, we distinguished between the green tide and non-green tide features in northern Jiangsu province offshore area. Five other models were compared with our developed identification avenue, including MLC, RF, SVM, MLC with multi-band ratio method, and SVM with multi-band ratio method. The results showed that the two vegetation indices, NDVI and FAI could markedly improve the accuracy of green tide information extraction. The RF model, which combined these two vegetation indices, provided a Kappa coefficient of 0.98 and an overall accuracy of 99.92%, outperforming the other five models. These findings of our study could offer, to some extent, the theoretical and operational supports for the future related research and the scientific management of the ecological and biogeochemical processes in marine environments.