Abstract: To investigate the dynamic and thermodynamic structure of a disaster-causing rainstorm induced by the " train effect " in northern Guizhou Province and the transmission mechanism of the " train effect " , based on the data of 521 automatic weather stations , radiosonde data , Doppler weather radar data and ERA5 hourly reanalysis data in Zunyi , Guizhou Province , this paper analyzes the convective triggering conditions , dynamic thermal structure and meso-scale system propagation characteristics of the " train effect " during the disaster-causing heavy rainstorm on the night of September 11 , 2021 . The results show that : 1 ) The meso-scale convective system continued to impact the west of Zunyi from west to east , forming a " train effect " , which was the most significant feature of the disaster-causing heavy rainstorm process . The key factor for the " train effect " to occur and eventually lead to the heavy rainstorm was that the high-altitude guiding air flow was parallel to the convective system. 2) The " train effect " occurred under the background of strong divergence at 200 hPa and a plateau trough moving east at 500 hPa. The two typhoons and the Bay of Bengal storm provided abundant water vapor and energy to the rainstorm area , and the low-level meso-scale convergence disturbance was the primary triggering mechanism of this rainstorm process . 3) The pseudo-equivalent temperature difference between 500 hPa and 850 hPa is a good indication of convective instability , and the coincidence area of positive vorticity center and negative divergence center is a good indicator for heavy precipitation . In this case of heavy rainstorm , there was a meso-scale vertical counter-circulation in the east of the low-level meso-scale convergence system , and the coupling of high and low air flows strengthened the vertical motion on the west side of the circulation . Finally , it developed into continuous upward motion in the rainstorm area , providing superior lifting conditions for the occurrence of the " train effect " . In a word , this paper analyzes the causes of the " train effect " in the heavy rainstorm case , and the conclusions are helpful to further deepen the understanding of the " train effect " propagation mechanism of local heavy precipitation , and can provide a reference for forecasting the similar heavy precipitation .