Using the data of densified ground automatic weather stations (AWS), Doppler weather radar, Himawari-8, and ERA5 reanalysis, the mechanism of the convective precipitation as a result of the motion and evolution of the upstream convective storm on 1 June 2019 during the meteorological support for maritime satellite launching is analyzed. The results are listed as follows. 1) The coincidence of convergence line and dry line triggers the newborn convection cell and the Weifang storm is formed. The strengthening during the eastward moving of the Weifang storm and the turning of the Liaocheng storm after entering Yantai cause the convective precipitation in Shandong Peninsula. 2) The Weifang storm moves eastward under the guidance of the westerly flow, propagates in the direction of high temperature and humidity along the convergence line, and the intensity increases. After entering Yantai, the Liaocheng storm turns to go southeast under the guidance of the west-northwest steering flow, propagates toward the water vapor convergence zone, and its horizontal scale increases. 3) The propagation direction of the Liaocheng storm after entering Yantai is opposite to that of the wind at 850 hPa, yet the propagation direction of the Weifang storm during the development stage is different from the opposite direction of the wind at 850 hPa, as the wind speed at 850 hPa is too small to affect the propagation. 4) It is very important to conduct short-term monitoring in the meteorological support process for major events. The birth time of cumulus on the high-resolution satellite cloud imagery is earlier than that observed by the radar, which can discover the precursor of convective initiation and propagation in advance. The combination of the data of Doppler weather radar and densified automatic weather stations can comprehensively judge the advection and propagation of convective storm. It is necessary to consider the impact of the motion of upstream convective storm on downstream areas when the local dynamic forcing is weak or the area is on the edge of the weather system.