In order to explore the temporal and spatial variation characteristics and risk occurrence probability of extreme climate in Hunan Province, selecting 12 extreme precipitation indexes and 16 extreme temperature indexes based on the daily meteorological observation data of 32 meteorological stations in Hunan Province from 1961 to 2017, and the linear trend method, M-K trend test method, Kriging interpolation and other methods were used to explore the temporal and spatial variation characteristics of extreme climate in Hunan Province, and the information diffusion model was used to evaluate the extreme climate risk in Hunan Province. The research shows that in the past 57 years of Hunan Province, the overall trend of extreme precipitation indexes is relatively gentle, and most extreme precipitation indexes are spatially higher in the east and lower in the west, and higher in the south and lower in the north. The overall change trend of the extreme temperature index shows a significant warming trend, and the index representing high temperature showed a decreasing trend from southeast to northwest in space. The risk assessment of extreme precipitation in Hunan Province shows that the risk of extreme precipitation in northwestern Hunan is greater, while the total amount of precipitation in southeastern Hunan is greater. The risk assessment of extreme temperature in Hunan Province shows that northwest Hunan is a high-risk area with continuous high temperature, and Changde City has a high risk of extreme high temperature, which is about once every 2 or 3 years.