Abstract: Abstract: Droughts and floods occur frequently in Huaihe River Basin, which has a great impact on crop yield. Based on daily mean temperature and precipitation data of 140 meteorological stations from 1961 to 2014, the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) in each growth period of winter wheat were calculated, and quantitative analysis of climatic characteristics of winter wheat at different growth stages was carried out. Meanwhile, the standardized yield residual (SYR) was calculated to investigate the effects of dry and wet conditions on yield at different growth stages based on the winter wheat unit yield data of 20 sites from 1961 to 2012. Firstly, the variation tendency of mean temperature and precipitation in each growing period of winter wheat was analyzed according to the linear regression. The mean temperature rose significantly and the mean rainfall mainly showed a downward trend in each growing period. According to the Mann-Kendall trend method, the trend values of mean temperature and precipitation in winter wheat growth period were calculated and the spatial characteristics were analyzed. The mean temperature in the south was higher than that in the north and had an increasing pattern from east to west, the trend in the east was higher than that in the west and most of the sites had the highest level of trend in turning green and heading stage. However, the precipitation increased with the decrease of latitude, and the trend was consistent with the temperature in latitude. Secondly, according to the Mann-Kendall trend method, the trend values of SPI and SPEI in winter wheat growth period were calculated, and the increase trend of drought was the biggest in turning green and heading stage at the significant level of 0.05. Comparing the spatial features of SPI and SPEI changing trends, it was found that the drought-flood disaster was affected by temperature in whole growth period, turning green and heading stage and milking ripening period of winter wheat, and was affected by precipitation in growth period before winter and over-wintering stage of winter wheat. And the trend of drought indicated by SPEI was greater than that by SPI. Finally, the correlation between SYR and SPI/SPEI was analyzed using Pearson correlation method to determine the most relevant stage of winter wheat, and then the drought and flood situation of winter wheat was analyzed. There was negative correlation between SYR and SPI/SPEI except growth period before winter, with the highest correlation in turning green and heading stage. When moderate drought or humidity occurred, the yield of winter wheat began to decrease. This research is of guiding implications to the prevention of disaster and yield reduction of winter wheat in Huaihe River Basin.