By using the hourly precipitation data of 1 597 stations in Jiangxi warm season from 2010 to 2016, ERA Interim, four times a day 0.125°×0.125° reanalysis data and the sounding data of Nanchang and Ganzhou, 84 cases of major flash heavy rain were selected, and five conceptual models of major flash heavy rain were established. They are cold front type, southwest jet type, the subtropical high type, warm shear type and typhoon type, and each type accounts for 29%, 40%, 11%, 12% and 8%. The average process maintenance time is 4.9 h, 5.6 h, 4.4 h, 5.5 h and 6.7 h; the average precipitation intensity is 31 mm·h^-1, 27 mm·h^-1, 45 mm·h^-1, 30 mm·h^-1 and 36 mm·h^-1. The cold front type, southwest jet type and warm shear type appear in May and June, the subtropical high type mainly occur in July, and the typhoon type occurs in July, August and September, but mainly concentrated in August. As for the high frequency area of flash heavy rain, cold front type, southwest jet type and warm shear type are mainly concentrated in the Poyang Lake Plain, the subtropical high type is mainly concentrated in the west side of Wuyi Mountain, and the typhoon type is mainly concentrated in the northeastern Jiangxi. The characteristics of environmental parameters are: the average CAPE of cold front type, subtropical high type and typhoon type is 1 200 J·kg^-1, and the southwest jet type and warm shear type are among 500 to 1 200 J·kg^-1. CIN is basically among 20 to 60 J·kg^-1. The K index of the typhoon type is higher than 38 ℃, and the other four categories reach to 32 ℃. The S index is basically less than -1.1 ℃. About 75% T₇₀₀-T₅₀₀ is above 13 ℃, and 75% T₈₅₀-T₅₀₀ is above 23 ℃. In regard to 850 hPa θ_se, the cold front type and southwest jet type greater than 340 K can be obtained, but the other three types need to be higher than 345 K. The height of warm clouds should be higher above 4 000 m. The lowest of the surface T_d southwest jet type and the warm shear type is 21 ℃, the second is the cold front type, the threshold is 22 ℃, and the typhoon type is 24 ℃. Most of the PW is above 50 mm, and the average is about 60 mm.