Abstract: The application of digital twin in basin comprehensive management is still under exploration.For promoting deeper application of digital twin technology in water conservancy filed, we summarize the experiences in the construction of digital twin of Three Gorges Reservoir region, and introduce some key technologies applied in the construction process.Through the intelligent construction tool for forecasting scheme system, real-time forecast-scheduling mutual feedback technology, deducing technology of water projects dispatching rules, whole-chain smart hydrological forecast method, we realize the intelligent forecasting and simulation of the basin.Based on the LBS technology, we propose a targeted release method for flood forecast and early warning information, a two-way intelligent interaction between users and management organization is achieved.Meanwhile, we develop a scheme analysis and display methodology that is characterized as multi-dimensional with macro-scopic, medium-scopic, micro-scopic, and whole scene with 2D,3D and mixed reality.Based on this and combining with intelligent forecasting and pre-warning, we achieve the forecast based scheduling rehearsal and assisting the accurate decision-making.The set of technologies mentioned above have achieved better application results in the flood control safety and the analysis of inundation impact in the Three Gorges Reservoir region, which can provide a reference for the construction of digital twin basins.