Abstract: Phase 6 of the Coupled Model Intercomparison Project (CMIP6) will provide more abundant global climate model data in the field of climate change projection, and its scientific combination scenarios of Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs) incorporates the impact of socioeconomic development. The new scenarios will provide more reliable possible results of climate change. The first flood in the Huaihe River Basin (HRB) has exceeded the safety guarantee water level. Therefore, research on possible changes in the future climate of the HRB is particularly important. This study downscaled 5 CMIP6 global models which included scenarios of SSP1-1.9, SSP1-2.6, SSP4-3.4, SSP2-4.5, SSP4-6.0, SSP3- 7.0, SSP5-8.5， and analysed the spatial and temporal changes of the annual temperature and precipitation in the HRB during 2021－2100. The areal averaged temperature shows an upward trend during 2021－2040 under SSP-RCP scenarios relative to the reference period (1995－2014). The areal averaged annual precipitation in the HRB will increase during 2021－2040. The increasing precipitation will be mainly located in the middle of the study area, and extreme floods will most likely to occur in the entire watershed. Comparing with the CMIP5 studies, it is found that under the SSP-RCP, warming will faster in the future, and the precipitation will increase obviously in the HRB.