Abstract: On June 24, 2017 and September 30, 2019, there were two serious geological disasters in Yunnan Province, causing heavy casualties and property losses. By using NCEP reanalysis data, ground automatic station observation data and Doppler weather radar detection data, the weather causes of the two disasters were analyzed. The results showed that the '6.24' landslide disaster occured during the main flood season of summer, which was caused by the long-term convergence of cold and warm air. There were several regional precipitations during this period. The radar was mainly composed of stratocumulus mixed cloud, and the characteristics of convective rainstorms were not obvious. The '9.30' mudslide disaster occurred in the autumn with a sudden change of atmospheric circulation. The cold air and warm air were weak, and the regional precipitation caused by the large-scale system was not very strong. Single-point convective strong precipitation caused by local geothermal action was the main cause of disasters.