According to the actual situation of Guihu Hanjiang grand bridge project,and based on the Navigation Standard of Inland Waterway (GB 50139—2004) and relevant research achievements by the Ministry of Transport (No.2003-335-343-42),we demonstrate the influence of the towed alongside,oblique cross,cross current,and turbulent flow on the navigation clearance dimension of Guihu Hanjiangr grand bridge,and determine the navigation clearance dimension at last.It provides reference example and specific computational model for similar designs of crossing channel structure.