Abstract: The 38 rainfall stations and 6 basic hydrological stations with a hydrological monitoring period of 30 years from 1991 to 2020 in Baoshan City of Yunnan Province are selected as representative stations. According to the measured series of meteorological and hydrological data, the hydrological statistical analysis method and GIS spatial analysis technology are used to analyze and study the regional rainstorm weather system, rainstorm regional distribution, interannual variation law and rainstorm intensity frequency characteristics with the watershed or representative hydrological station as the unit; Analyze and explore the flood types, distribution patterns, interannual variations, peak flood modulus, and frequency of excessive floods at major river hydrological stations. The research results can provide reference for calculation and design of rainstorm and flood analysis, hydrological forecast and early warning, and rainstorm and flood disaster prevention.