Abstract: The Yalong River Basin is the third largest hydropower base in China. Accurately simulating the future climate change in the Yalong River Basin can provide a scientific basis for the rational and efficient development of water resources in the basin. In order to evaluate and simulate the future climate change in the basin under different scenarios, this paper uses the data of 13 meteorological stations in the Yalong River Basin from 1970 to 2005, it adopts the MIROC climate model data in the Coupled Model Intercomparison Project phase 5（CMIP5） and it passes through the Statistical DownScaling Model（SDSM） downscales low-resolution raster data to measured site data. In this paper, the coefficient correction method and the frequency matching method are used to couple and correct the deviation and frequency distribution of daily precipitation. In this paper, the coefficient correction method and the frequency matching method are used to couple the correction of the deviation and frequency distribution of daily precipitation. Finally, the corrected data is used to analyze the future climate change in the Yalong River Basin. The results show that（1） After the correction, the certainty coefficient of daily-scale precipitation is improved from 0.12 to 0.2；（2） the future temperature and precipitation in the Yalong River basin show an overall increasing trend；（3） Under the three emission scenarios of three different representative concentration pathways（RCP2.6, RCP4.5, RCP8.5）, the future maximum air temperature in the Yalong River Basin will increase by 0.71, 1.16, and 1.35 ℃, respectively. The increase in December is more obvious; the future minimum temperature will increase by 0.72, 0.83 and 1.08 ℃ respectively, and the increase will be more obvious in August, September and December.（4）Under the three emission scenarios for the future period 2022-2100, the future precipitation in the Yalong River Basin will show an increasing trend, and the average daily precipitation will increase by 117.6%, 131.7%, 124.2%; the largest increase in RCP4.5 precipitation in spring, and the stronger the radiation forcing in summer, the more obvious the increase in precipitation in Yalong River Basin. The increase in temperature and precipitation in the Yalong River basin in the future will increase the frequency of extreme weather events. In the future, the uneven distribution of water resources will be further aggravated, and natural disasters such as drought and flood caused by climate warming will have adverse effects on the construction and operation of hydropower stations. The analytic results can provide a scientific basis for the water resources development of Yalong River hydropower base.