An analysis of a continuous and extremely intense precipitation process is made by conventional meteorological observation data, regional automatic station encrypted observation data, ECMWF thin, GRAPES_MESO, FY-4 satellite cloud image, new generation weather radar and NECP 1°×1° reanalysis data in the central and southwestern parts of Heilongjiang from 08:00 on August 6 to 08:00 on August 8, 2019. This paper analyses the dynamic mechanism of the heavy precipitation process and the nature and distribution characteristics of the precipitation caused by it. The results show that: The heavy precipitation process can be divided into three stages and two types of precipitation echoes: convective precipitation in the saddle field connected to the cold vortex; mixed and convective cloud precipitation combined by saddle field and enhanced warm front; convective cloud precipitation formed by changing the moving path of cloud systems under the action of the residual vortex of the typhoon. The interaction of cold vortex, subtropical high pressure and typhoon were the fundamental causes of this process. The subtropical high pressure and the warm and humid airflow outside the typhoon cooperate with the cold vortex and cold air provide water vapour and unstable conditions for heavy precipitation. The narrow water vapour transport channel caused the spatial discontinuity of heavy precipitation. The low-level convergence line provided trigger conditions for heavy precipitation. The stable structure of the saddle field, the forced uplift of the southern foot of the Daxing’an Mountains, and the blockade of typhoons prolonged the duration of heavy rainfall.