Predicting the temporal and spatial distribution of Reference crop Evapotranspiration(ET₀) in the Poyang Lake Basin in the future climate scenario can provide optimal management of water resource in the watershed and provide basic data support for scientific response to the impact of climate change on agricultural production. In this paper, the daily meteorological data of 14 meteorological stations in Poyang Lake Basin from 1961 to 2014 were used to calculate the historical ET₀ by the Penman-Monteith formula; Based on the reanalysis data of the US Environmental Center(NCEP) and the CNRM-CM5 model in CMIP5 from 2006 to 2100. The prediction data in the RCP4.5 and RCP8.5 scenarios are predicted by the statistical downscaling model(SDSM) and the bias correction to predict the future ET₀ of the basin; Through M-K test, ordinary kriging interpolation and spatial autocorrelation, the temporal and spatial evolution characteristics of ET₀ in the basin from 1961 to 2100 were analyzed. The results show that:the simulation effect of NCEP reanalysis data and the stepwise regression scale reduction model established by ET₀ of the basin is good, and the accuracy of the scale reduction simulation results of CNRM-CM5 model is significantly improved after the deviation correction, which is suitable for the estimation of future ET₀ of the basin. The overall ET₀ of Poyang Lake Basin during the base period from 1961 to 2010 shows a decreasing trend, and the spatial distribution is high in the north and south, and low in the middle, showing obvious spatial differences. Under the scenario of RCP4.5 and RCP8.5, the ET₀ of Poyang Lake Basin in the next three periods shows an increasing trend in different degrees compared with the base period. ET₀ has strong spatial autocorrelation in both benchmark period and future scenario. In RCP8.5 scenario, the aridity index from 1961 to 2100 in Poyang Lake Basin, showing a more obvious rise and increased with time, the valley of drought conditions in most of river basin from 2011 to 2100 by the humid to semi-humid areas, aridity index decreases from south to north, the Gan river basin will be the focus of the Poyang Lake Basin in the future drought risk prevention area.