Abstract: To address the problems of survey and design platform for water diversion projects, such as large data carrying capacity, low rock identification efficiency, and difficulty in route comparison and selection, a digital twin platform architecture for water diversion project survey and design was proposed. This platform integrated key technologies such as GIS+BIM multi-source data fusion, image-based intelligent lithology identification, high-fidelity cloud rendering, spatial analysis-based route comparison and selection, and 3D one-map-based digital handover. Taking the Gongming Reservoir to Qinglinjing Reservoir Inter-connection Project as an example, the feasibility of applying this survey and design digital twin platform was demonstrated. The results show that the platform enables functions such as operating condition simulation, land compliance analysis, route alternatives analysis, geological profile analysis, and crossing and traversing analysis, thereby improving the efficiency and quality of survey and design work. The research results can provide a reference for promoting the construction of life-cycle digital twins.