Abstract: The spatial and temporal distribution of rainfall in the Pearl River is uneven, with obvious differences in annual and interannual, and drought in successive seasons and years occurs from time to time. In addition, the Pearl River Estuary is affected by the saltwater intrusion, so the situation of water supply in the urban agglomeration of Guangdong-Hong KongMacao Greater Bay Area is critical. At present, the lack of drought drilling ability and the low efficiency of emergency scheme preparation are barriers of drought defense in the Pearl River Basin. In order to further enhance the basin drought defense ability, according to the relevant technical requirements of digital twins construction and combined with the characteristics of the Pearl River Basin, this study improved the database plate of basinal monitoring data and river channel topography, and developed the technology for management of water model and efficient generation of emergency scheme preparation. A“FEDE(forecasting, early-warning, drilling and emergency plan)”platform for the drought prevention have diverse functions. There are multi-source drought dynamic perception, multi-model interactive forecasting, multi-element precision early warning, multi-scheme simulation drilling and intelligent generation of multi-scheme emergency plan. These diverse functions successfully support the drought defense and water supply of the Pearl River during drought period of 2021 to 2022, effectively improves the drought response capacity of the Pearl River Basin. Moreover, it provides a reference for the construction of digital twins in the Pearl River Basin.