Abstract: The warm sector rainstorm occurred in the southeast of Hami in Xinjiang on 31 July 2018 was analyzed by automatic weather station data, conventional meteorological data, the Black Body Temperature (TBB) of FY-2E satellite data and NCEP FNL reanalysis. The results show that: (1) the weather process was a regional warm sector rainstorm in the southeast of Hami, which occurred under the background of large-scale circulation of the eastern South Asian high. The rainstorm zone was located in the right side of southwest jet stream in 200 hPa, the confluence area on the 500 hPa from southwest stream before central Asia low vortex and south airflow from western Pacific subtropical high on the west side, front convergence zone of southeast jet stream outlet zone on the 800－700 hPa, the overlapping area of the warm shear line at 700 hPa and surface γ-scale shear. (2) The water vapor mainly comes from the Arabian Sea, the Bay of Bengal and the Yellow Sea, and the convergence of moisture flux from 700 hPa to 500 hPa was closely related to the location of the rainstorm. (3) The meso-β scale convective cloud and the meso-γ scale shear line at ground were detained in the rainstorm area. The vertical circulation was further strengthened due to the topography of the Tianshan Mountains that runs from northwest to southeast.