Abstract: To ensure bridge safety and eliminate the threat of flood disaster,it is particularly important to conduct a detailed flood control risk analysis on the proposed bridge before the bridge construction. An efficient flood risk analyze model of bridge is established by using finite volume method combined with Delaunay mesh generation method which can adaptively refine the mesh. By locally refining the mesh around the pier,the large mesh size of large-scale river channel is maintained. Consequently,the mesh number is reduced and the calculation efficiency is improved. Comparing the results of water level and velocity calculated by different mesh models with the analytical solution,a greatly reduce of the mesh number is achieved meanwhile a high calculation accuracy is maintained by the local mesh refinement method. The numerical model is then used to analyze the flood risk of a bridge project. The results show that the construction of the bridge reduces the velocity near the pier and increases the velocity between the piers by about 0. 5 m/s.The upstream and downstream section velocity of the bridge are reduced by about 0. 2 m/s. The upstream and downstream water level of the bridge are increased slightly. The maximum water level around the bridge is 540. 70 m,which is lower than the minimum bottom elevation 540. 94 m of the bridge,under the design flood standard. The bridge can meet the flood control requirements of the river.