The spatiotemporal distribution of shorttime severe rainfall with different intensities was analyzed by using the hourly precipitation data of automatic weather station and regional automatic weather station, the NCEP/NCAR 1°×1° reanalysis data and the sounding data during 2010-2016. It is concluded that the weather pattern of the shorttime severe rainfall events in South Xinjiang has seasonal and regional characteristics obviously. Based on the characteristics of the environmental background of typical shorttime severe rainfall, three conceptual models of shorttime severe rainfall were established: Central Asia lowtrough (vortex) type, Siberian lowtrough (vortex) type and westerly shortwave type. The ambient background of the shorttime severe rainfall events in South Xinjiang was analyzed by the temperature and humidity profiles of seven sounding stations, ground dew point temperature, T850-T500, T700-T500, convective available potential energy (CAPE), convective inhibition (CIN), uplift condensation height, 0-6 km vertical wind shear etc. For shorttime severe rainfall Type Ⅰ (whole layer wet), shorttime severe rainfall Type Ⅱ (under the wet dry) and shorttime severe rainfall Type Ⅲ (upper dry wet), before the occurrence, there are abundant atmospheric water vapor, a certain CAPE obvious vertical wind shear as well as low 0℃ layer height, thick warmth cloud thickness and other characteristics. The appropriate CIN is favorable for the accumulation and explosion of the convective unstable energy, promoting the occurrence of shorttime severe rainfall. For the shorttime severe rainfall Type Ⅳ (dry adiabatic), the atmospheric stratification is relatively dry, and the T850-T500 and T700-T500 are relatively high. The Type Ⅰ (low vertex) and Type Ⅱ (low trough) are the main types of shorttime severe rainfall events in South Xinjiang which are often seen in the central and western parts of South Xinjiang, from mid summer to the end of summer, due to the influence of the Siberian lowvalue system (low vortex, low trough) type and lowvalue system in Central Asia (low vortex and low trough) type in the middle and southern regions of the southern part of China.