Abstract: Based on the precipitation data from national meteorological stations and intensive automatic weather stations in Sichuan Province over the past ten years (2010-2019), the temporal evolution of mountain rainstorms in climate scale over Sichuan are studied. By dividing the rainstorm events into rainstorms in western Sichuan (SC-A), rainstorms in northeastern Sichuan(SC-B), and rainstorms in western and north-eastern Sichuan(SC-C), statistical analysis yielded the following results:(1) The frequency of mountain rainstorms in Sichuan over the past 10 years shows a decreasing trend year by year, which is in contrary to the trend of accumulated rainfall and geological disaster. Both the fre-quency and intensity of SC-A shows an increasing trend in the past decade and the SC-B shows a trend with irregular fluctuations. At the same time, the SC-A shows a higher frequency than the other two events. (2) In the annual change of rainstorm peak, SC-A rainstorm peak is generally higher than the other two types of rainstorm. During the 10 years, except for the increase trend in August, the peak rainfall intensity in other months has no obvious linear increase or decrease trend. (3) The trends of accumulated rainfall and frequency of the three types of mountain rainstorm events were consistent, increasing from May to July, reaching the highest in July, and then gradually decreasing from July to September. The main feature is that the heavy rains in SC-B occur during May and September while the heavy rains in SC-A occur from June to August. (4) The frequency of strong precipitation at night is much higher than that during the day, mainly at 00-06. Furthermore, strong precipitation at night is more likely to occur in SC-A among the three types of mountain rainstorms.