Accurately and in real-time understanding the changes in the scope and species communities of intertidal wetlands is an important foundation for achieving sustainable development and management of wetland intertidal zones. In recent years, global warming, rising sea levels, and human activities such as coastal development, reclamation, and aquaculture have caused serious damage to the intertidal zone. At present, there is a lack of systematic research on the classification of mangrove tidal flats in the intertidal zone of Guangxi. In order to achieve large-scale and high-precision extraction of intertidal resources in Guangxi, this article was based on GEE (Google Earth Engine) platform, using Landsat series image data of Guangxi coastal zone from 2012 to 2022, and threshold segmentation processing of the images. The various remote sensing features under the influence of tidal dynamic inundation were analyzed, and the intertidal zone range of coastal wetlands in Guangxi was extracted. Achieved the classification of tidal flats and water bodies, mangrove vegetation, and non-mangrove vegetation in the study area, with areas of 5 641.67 hm², 1 625.29 hm², and 2 156.04 hm² respectively. The overall classification accuracy reached 93.3%, with a Kappa coefficient of 0.9.