The formative causes of a shorttime convective rainstorm on 19 July 2012 at Atux in Xinjiang is analyzed based on multiple data including surface, radiosonde, Doppler weather radar, 6h 1°×1° NCEP reanalysis data, and automatic station data. The results show: (1) The weather process was triggered by the upward movement and instability energy release of a mesoscale cyclone at low levels on the background of a vortex located over the south Xinjiang. (2) The invasion of cold air was one of important reasons for the convective development, and the smallscale synoptic systems in surface also contributed to instability energy release. The basic convective conditions such as vorticity and divergence field configuration, vertical speed, lowlevel easterly jet, and strong unstable energy were fulfilled and enhanced by the severe vertical wind shear. (3) The corrected sounding data of Kasha was more indicative of severe convection potential forecast and still need further verification. (4) According to Doppler radar data, the strong echo reflectivity, severe vertical wind shear, richer vertical integrated liquid, and higher echo top have close relation with the development and precipitation of the weather process.