Based on the 2016-2020 summer hourly precipitation data and ERA5 reanalysis data of Zunyi City, this paper analyzes the temporal and spatial distribution characteristics of short-term heavy precipitation in summer in Zunyi City, and calculates the physical quantity characteristics of short-term heavy precipitation occurring in the afternoon and before the second half of the night, and draws the following conclusions: (1) The diurnal variation of short-term heavy precipitation in summer in Zunyi presented a bifrontal structure, with the peak value at night mainly occurring in June, and the contribution of peak value during the day mainly coming from July to August. In June and July, the short-time heavy precipitation is more in the night than in the day, while in August, the short-time heavy precipitation is more in the day than in the night, and it is mostly in the afternoon strong convection. The anomaly probability of short-time heavy precipitation in summer in Zunyi City is greater at night than in day. (2) The mean value of night rain was significantly higher than that of day rain in 6 counties, and it was more than one times that of day rain. Only Fenggang and Meitan had the mean value of night rain lower than that of day rain. The diurnal variation structure of 7 counties was obvious, and Renhuai had the obvious four-peak structure, which might be related to the topographic distribution of high west and low east of the city. (3) The probability of short-term heavy precipitation in summer in Zunyi City is relatively high in the western and northern regions. The western region is mainly concentrated in the valley region and the northern region is mainly concentrated in Loushan Mountain Range. The average number of short-term heavy precipitation stations gradually decreased from June to August, and the stations with more than 10 stations gradually pushed and decreased northward, which may be related to the westward extension and northward lifting of the subtropical high. (4) Short afternoon heavy precipitation at high altitude stations has lower requirements on CAPE, K and LI, while low altitude stations need better uplift and warm and humid conditions at middle and low levels. Temperature difference between 850hPa and 500hPa at high altitude stations is higher than that at low altitude stations. (5) Compared with 14:00, the requirement of CAPE, LI and T850-500 for short-time heavy precipitation occurred in the late night was lower, and the mean value of four stations of the rise index was higher than 0℃, which was not as good as that in the afternoon. The requirement of K index of short-time heavy precipitation in the late night was higher, and the requirement of atmospheric precipable water was also higher, but mainly the high-altitude stations were higher.