In recent years, with the development of sponge city construction, the research on urban stormwater management by Chinese scholars has been deepened. However, the problems related to the construction of sponge city are becoming increasingly prominent. The principle problem is that the technology of water safety analysis for large-scale water accumulation in urban areas is relatively weak, which makes the construction of large-scale sponge city become a mere formality. Taking the built-up area of Yiliang County as an example, the relevant literature are reviewed and the water points are investigated. With the powerful function of ArcGIS tools, the comprehensive analysis of various indicators of urban area is carried out, and finally the distribution map of water security sensitive areas in built-up areas of Yiliang County is obtained, so that different stratigies could be formulated during the construction of sponge city construction can formulate different strategies according to the water security sensitive situation of each area, which is of significant reference for the construction of sponge city in the future.