Abstract: The main canal of the middle route of the South-to-North Water Diversion Project, to the north of Anyang River, is affected by the cold temperature in winter, and there will be different degrees of ice conditions, which affect the operation control and water delivery efficiency.To effectively promote the high-quality development of the follow-up projects and alleviate the contradiction between water supply and demand during the freezing period, based on the prototype observation data of winter ice conditions in recent years and the operation practice of water diversion during the freezing period, the evolution characteristics of winter ice conditions in the main canal of the Middle Route, the current water transportation dispatching mode and the effect of safeguard measures were analyzed.The results showed that:(1) The occurrence range of winter ice conditions in the main canal was basically in the Beijing-Shijiazhuang section, and the freezing and thawing conditions in the north and south canals were not synchronized.The main ice conditions were shore ice and flowing ice, so the risk probability of an ice jam was low.At the same time, the water conveyance time during the freezing period was relatively short, and the freezing duration of a large range of ice sheets was less than one month.(2) The current operation mode of water conveyance under the ice cover with small flow and high water level had the characteristics of high safety and good adaptability to meteorological conditions, but the water conveyance capacity of the channel would be greatly limited.(3) Prevention measure was the main treatment adopted in the Middle Route currently, and the integrated measures of "blocking, disturbing, melting, draining and salvaging" and various management measures were effective, which could be used as a reference for similar water conveyance projects during the freezing period.