Abstract: Based on the conventional meteorological observation data, NCEP FNL reanalysis data, FY-2 satellite cloud image and radar data, a persistent heavy rainfall in Meishan from 15 to 18 August 2020 was studied. The results show that: (1) The coupling of plateau vortex and southwest vortex is the influencing system of the heavy rainfall, and the strong and stable subtropical high forms obstruction, and the cold advection and the strong water vapor transport in the middle and low levels cause the persistent heavy rainfall weather. (2) Cold up and warm down, unstable atmospheric stratification. Low-level convergence and high-level divergence promote the development of convection. The ascending motion of heavy rainfall process is significantly enhanced. There is strong water vapor convergence in the low-level, which is beneficial to water vapor accumulation and provides important water vapor conditions for heavy rainfall. (3) Heavy rainfall occurs in low brightness temperature convective clouds, and convective clouds have strong vertical upward motion, strong radar echo, and formed a jet axis, which is conducive to the occurrence and continuation of heavy rainfall.