Abstarct: Nowadays by development of different sciences and technologies, understanding various phenomena and exception their complex mechanism is easy. Fluids and Hydraulic science isn’t exception to this rule. By development at different topic such in computational fluid dynamic and the growing number of different models to evaluate the types of river phenomena, Understanding the complex changes in flow and provide a reliable solution to prevent environmental damage easier. River confluence and their multi_branching and the pattern of flow and sediment in these areas, are always interesting and important topics for researchers in the field of hydraulic science. However, most of the researches in this field are experimental rather than numerical, but the laboratory investigations has various restrictions. In this research, various flow and sediment transport are modeled by using 2D CCHE2D program for different critical parameters of the flow. At first a model was validated using experimental results and then flow parameters such as velocity, froud number, Shields number and sediment levels were computed for different parameters for discharge, width and angle of intersection. Also the area of flow separation as well as an important area for the confluence studied and How to change the velocity and align of bottom sediments in this section checked at the end different researches were suggested for better understanding of flow and sediment transport in confluences.