In order to effectively respond to extreme events in the field of flood and drought disasters that may occur,it is imperative to pay attention to factors such as population density and economic development.Taking Ruijin city as an example,the urban water level surface is constructed combined with the water level data of the urban control section（Ruijin water level station）and the measured section of the upstream and downstream of Jinjiang river,by using the inverse distance weighted interpolation model in the ArcGIS extension module.The results show that when Ruijin city encounters excessive standard flood,except for a few high-lying areas on the left bank of the Jinjiang river,the remaining areas are more affected by the flood,and the main county area on the right bank is relatively less affected,with nearly half of the urban area,by the excessive flooding.The results can provide decision basis for flood control department of Ruijin city.