The Fujiang Bridge of Chengdu-Dazhou-Wanzhou High-Speed Railway is in the complex bridge-group reach. The left bank of the bridge is adjacent to a large wetland park，which intrudes into the navigable hole of 80 m on the left bank of the bridge for the new Dazhou-Chengdu Railway and occupies part of the navigable net width. This worsens the flow conditions in the bridge area，and the bridge area cannot meet the Class V channel standard. This study analyzes the regulation effects of four different dredging schemes by using two-dimensional mathematical flow models and ship maneuvering simulation tests. The results indicate that when Scheme 4 is employed for the large-range dredging of the wetland park on the left bank，and the old Dazhou-Chengdu Railway in the upstream is demolished，the maximum flow velocity in the bridge area is reduced by 0.46 m/s，a reduction of 21.88%，and the maximum lateral flow velocity is reduced by 0.33-0.65 m/s，a reduction of 33.67%. The optimal dredging scheme can effectively improve the navigable flow conditions of the channel in the bridge area and thus ensure navigation safety.