Abstract: It is a key problem for engineering construction that whether or not the reservoir water will flow along fault F1 to downstream after impoundment, and then change the water quantity, temperature and quality of the hot springs developed along the fault. In view of this, the genetic mode of hot springs was explained through the analysis on regional geological conditions, water chemistry and isotope characteristics of hot springs. On this basis, the influence of reservoir seepage to downstream hot springs was evaluated from qualitative and quantitative analysis by geological analysis and numerical simulation. The results showed that: the hot springs are ascending springs, and their formation are related to the groundwater deep circulation. The circulation system is relatively independent and mixed with shallow groundwater only in the process of spring water discharging; the hot springs will discharge normally after completion of the hydropower station; and the influence of reservoir seepage along the fault is very little on water quantity, temperature and quality of the hot springs.