In order to explore the impact of materials on the working performance of large geotextile sandbags in the waterway regulation project, a numerical analysis model was established based on the engineering background by using finite element method, revealing the stress and deformation mechanism of geotextile sandbags under different sandbags materials, providing support and basis for the selection of large geotextile sandbags materials in actual projects, and a proposal was made to use 510g/m2 polypropylene filament woven fabric and 150g/m2 non-woven fabric to prepare composite sandbags. Finally, the application of the first phase of the Yangtze Estuary South Passage Channel Regulation Project is taken as an example to demonstrate the safety, applicability and efficiency of the technology, and the relevant achievements can provide technical guidance and application reference for relevant projects.