Aiming at the problem of ice conditions in winter for the Middle Route of the South-to-North Water Diversion Project, taking the Hebei section of the project as the research object, the formula of overall total heat variation of canal sections of the target unit was derived through the theory of heat balance. The single factor local analysis method was used to select the evaluation index. Then, based on the idea of probability theory, the joint density function between evaluation indexes was built, and the probability of meteorological events, change rate of total heat change, the risk level of ice conditions was correlated, so as to carry out the risk assessment of ice conditions in channels. The risk analysis results of ice conditions in Hebei section of the Middle Route of South-to-North Water Diversion Project from January 6th to 8th in 2021 show that, in the whole process of heat exchange, the short-wave radiation, evaporation and convection are the main factors, and the heat loss in the channel at nights is significantly greater than that in the daytime, which increases the risk of sudden ice conditions at nights. In addition, although the risk level of Shahe gate-terminal section is the same as that of other sections, its heat loss per unit area is obviously higher than that of other sections, and it is close to extremely high risk. In practice, real-time monitoring should be strengthened and relevant protection measures should be taken for this section.