Abstract: A one-dimensional unsteady and non-equilibrium transport mathematical model is presented.It may not only be used to simulate the water level,discharge,sediment concentration and sediment deposition when the Yellow River intruding into the Weihe River,but also be used to calculate the water and sediment of a reach which has two-direction velocity or tributary inflow.The verified results show that the model can simulate the whole process of the changes of hydrologic and sedimentary elements in the downstream of the Weihe River.