Based on the daily precipitation data of 83 stations in Guizhou from 1961 to 2021, the single station autumn rain processes in Guizhou were defined, and the comprehensive intensity evaluation index of autumn rain was constructed, which comprehensively considered the longest period of autumn rain days, the accumulated days of other periods, and the proportion of autumn rainfall in annual rainfall, the spatial-temporal characteristics of autumn rain and its relationship with 500 hPa geopotential height in northern Hemisphere and global SST are studied. The results show that the index shows a belt distribution from northeast to southwest, decreasing from northwest to southeast; the inter-annual fluctuation of the index was relatively large, showing a downward trend at a rate of 0.064/10 a in recent 61a; according to the EOF analysis, the first modal spatial pattern was consistent in the whole region, which was the main mode of climate variability of autumn rain; the inter-annual variation cycle of autumn rain was 2~4 a; 1997 was the mutation point;in heavy autumn rainy years, the 500 hPa geopotential height over the Eurasian continent shows a "north positive and south negative" anomaly distribution,which was beneficial to the southward movement of cold air from the north, and the 850 hPa wind anomaly over the South China Sea and its surrounding areas was a significant anticyclonic circulation, which strengthens the transport of warm and wet air from the southwest; the effect of ENSO on autumn rain in Guizhou was asymmetrical, when the tropical eastern Pacific was warmer and the tropical western Pacific was colder in August, the autumn rain in Guizhou in EL Niño is heavier.