Abstract: From July 17 to 23, 2021, an extremely heavy rainstorm occurred in Weihui City of Henan Province, resulting in the third largest flood since the establishment of Huangtugang Station of Communist Canal in Weihui City, and the largest flood since the establishment of Jixian Station.Through the analysis of the causes, temporal and spatial distribution and characteristics of the rainstorm, it is helpful to understand the characteristics of extreme weather rainstorm.Through the analysis of flood source and composition, flood process, flood characteristics and flood recurrence period, it is helpful to understand the flood characteristics of this basin.This analysis of rainstorm and flood characteristics has reference for planning and design of Weihe River basin, flood forecast and flood control in Weihui City.