In recent years，the disaster by flood was occurred frequently in Jiangxi province． It often has a serious impact on the development of social and economic and the safety of people＇s lives and property． The flood disaster is inevitable，so how to prevent effectively is most important． In the case of Jiangxiang Dike，which is the most important of Jiangxi dike，the flood evacuation is analyzed based on the maximum flood，and considered with the combination of flood encounter in Ganjiang river and Poyang lake． And the flood evacuation route is planned by the space analysis method in ArcGIS，and the paper develops the flood evacuation map． The result is provided to the decision basis for rescuing operation about disaster prevention and reduction．