Abstract: Aiming at the river where there is a severe bed scour and remarkable river chanml process caused by river-bank collapse, a three-dimensional (3D) numerical model for water flow and sediment is established under the conditions of considering the river-bank erosion. A finite volume method combined with the unstructured grids is applied to dispersion of a governing equation, and the SIMPLE algorithm with the unstructured collocation grids is used to deal with the coupled problems of the pressure and velocities. The numerical simulation results are verified with the measured data from November 2011 to October 2012, and the calculated results agree well with the measured data. The numerical simulated results demonstrate that the model can reasonably simulate the water flow and riverbed processes in the Daliushu reach of the Yellow River. The locally-adaptive grid technique and locally-encryption grid technique on the basis of the non-orthogonal grids given by the numerical model can effectively improve the calculation accuracy and efficiency in the numerical simulation.