Stable hydrogen and oxygen isotopes can effectively trace the moisture sources of precipitation. Precipitation recharge has a significant impact on the stability of Hani Rice Terraces during the dry season. This paper selected the Quanfuzhuang River Basin in the core area of Hani Rice Terraces World Heritage as the study area during the dry season from November 2015 to April 2016. We analyzed the variation of precipitation isotope and its impact factors, and used HYSPLIT model to track moisture sources. The results indicated that:1) the Local Meteoric Water Line equation was δD=7.31δ¹⁸O+19.8 (R²=0.94, P<0.01, n=42), with smaller slope than the Global Meteoric Water Line and larger intercept. 2) The δ¹⁸O and d-excess rate rapidly increased in the early dry season, but δ¹⁸O rate was slow down in the late period, and the d-excess rate rapidly decreased, which showed that the moisture sources had time differences. However, the spatial variation was not obvious. 3) The multiple linear regression equation of δ¹⁸O and temperature, precipitation amount, and relative humidity during the dry season is δ¹⁸O=0.002P-0.86T-0.39H+38.22 (R²=0.96, P=0.05), indicating that the precipitation isotopic changes was the result of multiple factors during the dry season. 4)The backward trajectory model showed that there were main three moisture source routes during the dry season. The moisture vapor from South Branch of westerly and local transport were less, and the dominant southwestern monsoon accounted for about 70% in every month except February. 5) The precipitation amount was generally small during the dry season, but the precipitation at the end of the southwest monsoon provided water sources for irrigation in November. The precipitation from southwest monsoon next year was beneficial to fertilization and planting in April. The process provided necessary water source to guarantee the water demand of terraces during the dry season.