The application of GIS technology to flooding research has always been a hot spot for everyone to chase.This article was based on the GIS technology and Jiangxi water regime，ArcGIS and remote sensing image processing software were utilized to analyze the flood submergence of Poyang lake area in Jiangxi province，the submerged range，submerged depth and submerged area we need were calculated，and the affected population and the damaged food were assessed，to produced the relevant thematic map.This study has good accuracy，practicability and scientificity，it provided a basic platform for further production of flood risk maps，flood control command dispatching and loss assessment of floods.