In order to enhance the cognition and building ability of numerical model of flow and sediment and improve the accuracy and reliability of the model, domestic and international researches about numerical model of flow and sediment and apply experience were summarized in this paper. The summary included aspects, such as cognition of model, choice of model, partition of grids, setting of parameters, calibration and verification of model, correction of common misunderstandings. From this paper, the building of numerical model is suggested to be based on objective physical processes. The model user should grasp basic knowledge of flow and sediment, understand the situation of flow and sediment in study area well and then build the numerical model reasonably and efficiently.