The invention relates to a river channel water and 
sediment real-time prediction method based on 
data assimilation, and belongs to the technical field of water conservancy projects. The method includes the steps of firstly, collecting topographic data of a 
water channel to be predicated, upstream boundary condition data, downstream boundary condition data and fracture surface data of the river channel, setting up a one-dimensional non-steady-flow and non-balance 
sediment transport model, and solving the model; secondly, conducting water and 
sediment model assimilation on real-time 
observation data while receiving the real-time 
observation data, and enabling the assimilation value to serve as an initial field for calculation; thirdly, calculating the changes of the future 
water level, the further flow and the future 
sediment concentration according to information of the initial field and the boundary condition data. According to the method, the 
water level and flow speed prediction function, the 
flood forecast function and other functions are achieved on the basis of data such as the assimilation real-time 
water level, the flow speed and the 
sediment concentration, and the method has the advantages of being strong in pertinency, comprehensive in function, convenient to use, practical and the like, can be applied to river channel flood real-time forecasting of great rivers, and provides the decision-making support for the practical 
flood prevention command work.