Clarifying the source of precipitation in the Three Gorges Reservoir (TGR) region is of great significance in understanding the ecosystem's water cycling response to extreme droughts. This study analyzes the stable hydrogen and oxygen isotope composition of atmospheric water vapor measured in August 2022 and precipitation from August to October in the TGR region, along with relevant meteorological data, to elucidate moisture transport characteristics. A three-component isotope mixing model was applied to estimate the contributions of recycled moisture (i.e., surface evaporation and transpiration vapor) and advective vapor to precipitation in the upper, middle, and lower sections of the TGR region. The results indicated that from August to October 2022, moisture pathways were oriented from southwest to northeast, with advective moisture transported from upstream to downstream along the reservoir mountain range. From September to October of 2022, the average contributions of vegetation transpiration (P_tr), surface evaporation (P_ev) and advected vapor (P_adv), to precipitation in the middle section of the TGR region were 35.4%±4.8%, 0.2%±4.9%, and 64.4%±9.6%, respectively. In the lower section, contributions were 27.9%±4.8%, 0.8%±3.9%, and 71.3%±8.6%, respectively. In August, when the high temperature and drought were most severe, the contributions in the middle section were 60.9%±3.3% for P_tr, 2.2%±3.7% for P_ev, and 36.9%±6.6% for P_adv, while in the lower section, they were 16.5%±1.8%, 2.6%±2.0%, and 80.9%±3.8%, respectively. The advective water vapor transported by southwesterly winds was the primary source of precipitation in the reservoir region, with recycled moisture mainly comprising vegetation transpiration and minimal surface evaporation. Rainfall in August 2022 was lower than in previous years, resulting in a slight enrichment of precipitation vapor isotopes in the lower section. In addition, the extreme heat and drought in August 2022 accelerated moisture cycling in the upper and middle sections of the TGR region, enhancing the dominant role of recycled moisture in the middle section while reducing the contribution of vegetation transpiration to local precipitation in the lower section.