Abstract: The cascade regulation of the Qingjiang River based on historical runoff is difficult to adapt to the needs of climate change, which will inevitably affect the safe and stable operation of cascade reservoirs and the development of profits. The SWAT model was built based on the spatial data and observation data of the Qingjiang Basin, and the future meteorological data of each station in the basin under the three scenarios were simulated by using the statistical downscale model. Then the runoff was simulated, and the power generation change of the Geheyan Hydropower station was analyzed. The results show that the simulated annual average runoff of the Changyang Station under three Climate scenarios of RCP2.6, RCP4.5 and RCP8.5 in the future is on the rise, and the annual average runoff increase is 6.0%, 8.7% and 13.2%, respectively. Under the above three scenarios, the average generation capacity of the Geheyan Hydropower Station increases by 3.4%~5.1%, 7.7%~10.3% and 13.4%~16.0% in 2020-2045, 2046-2070 and 2071-2100, respectively. This study can provide a theoretical reference for water resources management and power generation operation of the Geheyan Hydropower Station in the Qingjiang River Basin under climate change.