南水北调工程受限于当时规划设计和信息化总体建设水平，存在输水调度不能与沿线受水区实现供需最优 配置，水质监测自动预警程度不高、水污染突发事件应急处置缺乏科学决策支持及工程安全风险不能主动精准预 警等问题。为解决上述问题，基于南水北调中线工程的建设现状和数字孪生技术特点，从框架设计、技术路线规 划 2 个方面提出数字孪生南水北调中线工程的总体建设思路，并且围绕工程安全、供水安全、水质安全的“四预” 需求，详细阐述实施路径和重点建设内容，为数字孪生南水北调中线工程建设提供重要参考。

The Middle Route of the South-to-North Water Transfers Project is a major strategic infrastructure project to optimize the allocation of water resources and improve the ecological environment in China. However, due to the limited level of planning and information construction, there are a series of challenges, including that the water supply destination cannot realize the optimal dispatching of water transport to achieve supply and demand balance, the automatic degree of early warning in water quality monitoring is inadequate, the disposal of water contamination accident lacks scientific decision-making support and the engineering safety risks cannot be actively and accurately warned. In order to provide scientific and technological support for the construction of the digital twin of Middle Route of South-to-North Water Transfers Project, to provide a model for the construction of digital twins in other water transfers projects, and to support the acceleration of construction of digital twins in the national water network of China, this paper aims to build a unified data base plate, improve the ability of information infrastructure, build a digital twin Middle Route model platform and knowledge platform, and finally realize the precise decision support for the safe operation of the Middle Route and water resources scheduling on the basis of the Middle Route spatio-temporal information service map. Based on the construction status of the Middle Route of South-to-North Water Transfers Project and the characteristics of digital twin technology, the gap between the informatization status and the requirements of digital twin construction was analyzed. According to the requirements of digital twin construction, the overall thought of the construction of the digital twin of Middle Route of South-to-North Water Transfers Project from two frame design and technical route planning based on the construction status of the project and characteristics digital twin technology is put forward.The implementation path is elaborated in detail with the principle of “three safety” of engineering safety, water supply safety and water quality safety and the core objectives of improving the level of digitization, networking and intelligence of the project, and strengthening the four pre-functions of “forecast, early warning, preview and plan”. The key construction contents of digital twin platform, engineering safety application, water supply safety application, water quality safety application and standard specification system are clarified. Through the establishment of the standard system required for the construction and management of the digital twin of South-to-North Water Transfers Project with systematic thinking, it comprehensively covers the business areas of the South-to-North Water Transfers Project, and is unified and coordinated to meet the construction and management needs of the digital twin business of the South-to-North Water Transfers Project. Through the three-step construction of digital twin of Middle Route of South-to-North Water Transfers Project, that is, the local effect in the first year, the overall promotion in the second year, and the enabling application in the third year, the synchronous simulation operation and iterative optimization of the physical Middle Route and the digital Middle Route are realized, helping the Middle Route to play a greater role in the development of the national economy. As an important component of the backbone network of the national water network, the South-to-North Water Transfers Project should play a leading role in scientific and technological innovation, and make industry demonstrations in promoting the digitization of water networks, intelligent dispatching, automation of monitoring and early warning, strengthening the integration of physical water networks and digital water networks, and improving the level of science and technology and intelligence of water network projects, which provides an important reference for the construction of the digital twin of Middle Route of South-to-North Water Transfers Project.