Abstract: The Pioneer Street bridge crossing Xi-River in Fuxin is a typical urban bridge project. This paper introduces the main work of flood control impact assessment，the backwater and scouring calculation and so on. Based on the results，the bridge project has less affected to the river regime and backwater and embankments. This study recommends that in order to ensure the safety，both sides of the floodgates on the bridge should be closed during flood season. This study has important significance to flood discharge in river courses and dyke safety，as well as the bridge construction.