Under the influence of climate change the reliable design and safe operation of hydraulic engineering has become a hot issue for decision makers, researchers and the public. Taking the Qingjiang River Basin as the research target, and using fuzzy set analysis method to classify the daily rainfall data generated under different greenhouse emission scenarios (e.g., A2, A1B and Bl), the extreme precipitation series were simulated by generalized extreme value distribution (GEV) function. The results show that climate change has changed the precipitation structure, and its seasonal shift directly affects the flood season division. Under the three emission scenarios, the main flood season in the future will be postponed and shortened compared with the baseline period. The extreme precipitation in the future (e.g., 2011-2030, 2046-2065 and 2080-2099) is less than the baseline period, and this difference increases with the increase of the return period. The extreme precipitation in the main flood season is notably larger than that in the pre-flood season and post flood season. For extreme precipitation, the differences between periods are remarkably greater than those of emission scenarios.