Abstract: In order to quickly analyze the temporary inundation under the different controlled water levels of hydropower plants in flood seasons ,assess the possible inundation loss ,and to meet the needs of dynamic water level control in flood season of hydro- power stations ,a method for rapid determination of temporary inundation range considering backwater elevation was proposed. This method was based on python for the secondary development of linear interpolation tool on ArcGIS platform. By obtaining the back- water DEM and performing corresponding calculations with the reservoir area DEM,the inundation range of the reservoir area un- der different controlled water levels during the flood season can be obtained. The model was applied and verified in yantan Hydro- power Station of Hongshui River. The results showed that the proposed method can output the temporary inundation range within 8 s. Compared with classical hydrodynamic model HEC-RAS , the overall accuracy of the proposed model was 0 . 92 , which can greatly improve the analysis efficiency of the temporary inundation effect under the different control water levels of reservoirs.