The construction of digital twin Tanjiang River Basin is carried out to improve the fl ood control capacity. The digital twin Tanjiang River aims to meet the needs of fl ood control scheduling in the basin,with the goal of fi nely scheduling 22 large and medium-sized reservoirs and 7 cascade gates. Focusing on the core functions of “four pre”, data base plates,model platforms,and business applications are developed. For data base plates,a L1 level of basin and a L2 level of key areas and engineering projects are established. For model platforms,6 major types of water conservancy professional models are developed. For business applications,the prediction and regulation system platform with “four pre” functions is constructed,in order to achieve effi cient management of multi-source monitoring perception and data,to support centralized management,joint scheduling,and scientifi c decision-making of reservoirs, gates,and dams. It also can maximize the safety of fl ood (tide) in the basin,address the existing shortcomings of prediction and monitoring,improve the timeliness of engineering scheduling feedback,and provide a reference for standardized management of rivers and lakes. Thus,a basin joint scheduling platform is preliminarily formed. The project achievements were put into practice during the 2022 “Dragon Boat Water”,typhoon and rainstorms,which could help the joint regulation of reservoirs and sluices in Tanjiang River basin,and achieve the best benefi ts of fl ood control without inundation,water resources utilization.