In the past decades, Taihu Basin has witnessed rapid economic and social development. However, due to the lack of corresponding alternation in the economic growth mode, the water circulation system of Taihu Basin has been disturbed and destroyed, resulted in great threaten in the water security. As a key measure to ensure water security and an important measure to comprehensive water treatment in Taihu Basin, the water diversion project from Yangtze River to Lake Taihu has been launched since 2002. Supplementing drought with increased abundant water resources, suppressing the large-scale outbreak of cyanobacteria in Lake Taihu and improving water environment in the basin, prompt response to water pollution crisis to ensure the safety of water supply, the water diversion project has achieved remarkable comprehensive benefits which attracted extensive attention from social public. Based on monitoring data and published literatures, the paper reviewed the background, process and achievements of water diversion practice focusing on the scheduling mode, water quantity and quality ensure, flood-drought risk management and water diversion event-driven. The results show that water diversion project has resolved some key scientific questions of management through series of practices and exploration, and has become an important means to improve the carrying capacity of water resources and environment. Facing extreme climate and water cycle pattern changes of the basin, new demands and challenges emerged to ensure water security of the integrated high-quality development of Yangtze River Delta. It is suggested that multi-objective coordination scheduling should be explored, water diversion based on digital twin should be carried out, and water network construction should be promoted to maximize the comprehensive benefits of water diversion from Yangtze River to Lake Taihu.