In this paper, using the C-band dual polarization doppler weather radar data of Rongjiang in southeast Guizhou, conventional observation data and ground densified automatic station observation data, the circulation background, influence system and radar echo characteristics of the convective rainstorm weather process in eastern Guizhou from the evening to the night of September 6, 2021 are summarized and analyzed.It is concluded that (1) This weather process is under the background that the subtropical high extends westward and uplifts northward to form a high-pressure dam. The mid high latitude cold vortex trough and the short wave trough moving eastward from the plateau are in the same phase in eastern Sichuan, strengthening and moving eastward, leading the cold air to strike the eastern Guizhou from both sides of the northwest path and the northeast path, together with the south-north low level shear line that has been stably maintained for a long time, to jointly trigger the strong release of unstable energy and generate convective rainstorm weather.(2) After moving eastward to Tongren and Qiandongnan Prefecture, the eastern segment of the band convective echo gradually turns into the mixed precipitation echo of sheet cumulus and stratocumulus, which is stable and less dynamic for a long time. During the rainstorm, the echo has obvious characteristics of tropical warm cloud precipitation echo with low centroid and high efficiency; the VIL value is between 10 and 30 kg·m-2, and there is obvious jump phenomenon locally; the obvious wind convergence is maintained on the low elevation radial velocity map for a long time. (3) The radar polarization parameters in this process have the characteristics of producing heavy precipitation,The maximum ZH is between 40 and 60 dBz, ZDR is between 0.2 and 5dB, KDP ranges from 0.5 to 7.0 ° · km-1, CC is between 0.9 and 0.98, and≥0.98 at the maximum.