Through analyzing the dynamic conditions for torrential flood forming, the disasterbreeding environment, and the precipitation background, five parameters, including critical rainfall amount, annual precipitation, slope, the relief degree of land surface, and the annual number of heavy rain days, are identified as the main factors affecting the formation of flash flood disasters. Using the method of principal component analysis, the Chongqing torrentialflood disaster zoning model is established. Based on GIS technology, the spatial interpolation on various factors affecting floodinduced disasters by using inversedistance weighting method and then the calculation and segmentation for the raster layer are conducted. Chongqing is divided into four catalogues: high disasterprone area, disasterprone area, general area, and low disasterprone area, and the regionalization of torrentialflood disaster in Chongqing is achieved. The results show that Chongqing is an area attacked frequently by flood disasters. The high disasterprone areas are in northeast, with the annual occurrence frequency being more than 10 times; the disasterprone areas are in central and southeast parts, with the annual frequency more than 8 to 10 times; the low disasterprone areas are in western, with the annual frequency less than 6 times.