Based on conventional meteorological observation data of Zhejiang Province, ERA5 hourly reanalysis data (0.25°×0.25°) and blackbody brightness temperature (TBB) of FY-4A satellite, the two rainstorm processes occurring on June 3 and June 30 in 2020 were compared and analyzed. The results are as follows: (1) The rainstorm on June 3 (short for “6·03”) occurred in the background of monsoon trough, and there were southwest flow in front of the trough at 500 hPa and warm shear at 850 hPa over Zhejiang Province,while the rain storm on June 30 (short for “6·30”) occurred in the background of northeast cold vortex, there were confluence of cold and warm air at 500 hPa and cold shear at 850 hPa. For two rainstorm processes, their rainfall areas were similar, all concentrating in west Zhejiang and presenting east-west belt distribution. But for the “6·30” process, the rainfall area was wider, both the center rainfall and process rainfall were larger, the hourly rainfall intensity was stronger, and the duration of heavy rainfall was longer. (2) Both two rainstorm processes were convective unstable precipitation, but the heavy rainfall areas were in different positions of the jet stream. The “6·03” process was a warm shear type rainstorm in the warm region, the “train effect” of convective cloud clusters was significant and precipitation was located in the strong convergence area of water vapor flux in front of the jet. During the “6·30”, the Meiyu front was a westerly convergence frontogenesis, and the convective cloud clusters presented a backward propagation path, the precipitation was located in the strong convergence area of water vapor flux near the jet axis. The maximum convergence area of water vapor flux and intensity at 700 hPa corresponded to the falling area and intensity of heavy precipitation in the next six hours, which had a certain reference in rainstorm forecast in the Meiyu season. (3) Due to different precipitation types, the corresponding frontogenesis was different, and the height of the frontal zone indicating one hour heavy rainfall was also different. So in the forecast of rainstorm in the Meiyu season, the correspondence of different precipitation types and frontogenesis at different heights should be fully considered.