Based upon the theory of hydrodynamics, river mechanics, thermodynamics, river-ice hydraulics and mechanics of solids etc. , a mathematic model of the river-ice processes for the Yidan reach is constructed. 30-year long-term series comprehensive field observation data, including geomorphy, meteorology, hydrology, thermo-dynamics and ice regime, are used to simulate the water transfer process of the Yidan River during freezing period. The results show that steady ice cover can be formed by juxtaposition on the Yidan River, which achieves the goal of water transfer beneath the ice cover. In addition, the design discharge of the Yidan River water transfer project can be guaranteed during freezing period.