Abstract: This article takes the Jiaohua Reservoir as the research object, and studies the design of the digital twin flood control and dispatch system for Jiaohua Reservoir in accordance with the requirements of the "Technical Guidelines for Digital Twin Water Sector Engineering Construction" under the premise of insufficient historical hydrological data and operation data for the newly built reservoir. With reference to the hydrological data near adjacent river watersheds and the application of flood control and dispatch for reservoirs as the core, a digital twin support platform related to flood control and dispatch is constructed, including water sector professional models, forecasting schemes, historical scenarios, and operation schemes. The design of the digital twin flood control and dispatch system based on digital twin technology of Jiaohua Reservoir for flood control and dispatch forecasting, early warning, rehearsal, and contingency plans is studied, providing simulation tools for flood control and dispatch of Jiaohua Reservoir. The research results can effectively improve the flood control and scheduling management capabilities of the Jiaohua Reservoir project, and also provide reference for the digital twin design of the Jiaohua Reservoir project's water supply and transmission pipelines, hydropower stations, irrigation areas, water plants, and other engineering projects.