With the upgrading of the Yangtze River waterway,ships sailing often are threatened because of insufficient horizontal width in the navigation-obstructing river with the protruding point or large reef,so,we carry out a research on the generalized rock oblique flow structure and ship’s stress characteristics.Simulating the rock channel by software CFD combined with the 3D numerical simulation of the current,we know that the higher the current speed and the more the rock occupies,the longer influential distance on the flow structure of distance,and esp. the influential distance of the lateral velocity is more obvious； velocity is proportional to the lateral force of ship；the length-way influential distance from the generalized rocks on the ship is generally within 1 time the length of the ship both upstream and downstream,and the maximum value is at the 0.5 time ship length upstream.