Abstract: Due to the convergence of tributaries, in the confluence area and the main stream mixed with each other on top of the support, the natural river has changed the original flow pattern, forming complex water structure, which has a certain impact on the maneuverability and safety of inland river ships. Through numerical simulation test methods, based on the separated（MMG）hydrodynamic model, this paper systematically studies the navigable conditions of ships in the intersection area under different intersection angles, confluence ratio and channel width ratio, namely, the factors of drift angle and yaw distance. Based on the Design-Export response surface analysis software, this paper finds the dimensionless response function between the maximum yaw distance, intersection angle, confluence ratio and trunk and branch width ratio.