Using NCEP reanalysis data and the HYSPLIT model, the water vapor transport characteristics during a torrential rain on 25 June 2018 at Jinan Yaoqiang International Airport are analyzed. The results show that there are three major water vapor channels for this torrential rain. One is the northwestern air flow in the middle troposphere, another is the southeastern air flow near the western Pacific subtropical high, and the other is the northward air flow from the South China Sea. The water vapor mainly comes from the western Pacific and the South China Sea, and the contribution rate to the torrential rain is 46% and 42%, respectively. The water vapor from the northwestern channel is less, and its contribution rate is only 12%. Further analysis indicates that the water vapor transport by the western Pacific channel dominates at the bottom of the troposphere below 850 hPa, while the water vapor transport by the South China Sea channel dominates in the middle troposphere above 700 hPa.