Based on the data of 12 ground observatories from December 1968 to March 2018 in Qiannan Prefecture, the spatial distribution, initial time and duration of rainstorm and frozen weather in the past 50 years are analyzed. Meanwhile, 500hPa of the daily reanalysis data of 2.5 x 2.5 grid points of NECP/NCAR are used to explore 50 cases of Super-heavy freezing and heavy freezing in Qiannan. The results show that the frequency and duration of frozen weather are obviously related to its geographic location and geomorphological characteristics, especially in Weng"an, where the number and duration of frozen weather are the largest and the longest. No frozen weather has occurred in Luodian and Libo for 50 years. The average beginning date of frozen weather in Qiannan is from mid-January to the beginning of late ten days, and the average end date is in January. In the analysis of regional frozen weather circulation in the late ten days, the higher the location and intensity of cold high in high latitudes, the greater the possibility of regional frozen weather in Qiannan. Especially when the Pacific subtropical high extends westward, the frozen disaster is the most serious.