Abstract: 【Objective】 In recent years,drought and flood disasters occurred frequently in Ezhou City.This study discussed the spatiotemporal evolution characteristics of drought and flood in Ezhou City in the past 30 years. The research results can provide data and theoretical support for the reasonable construction of drought early warning evaluation indicators in Ezhou City.【Method】 The evolution and persistence characteristics of drought and flood in Ezhou city in recent 30 years were analyzed,and their influencing factors were explored by using Mann Kendall test,linear regression and path analysis based on the data of national meteorological stations and 1km high resolution grid data in Ezhou city from 1991 to 2020,in which the standardized precipitation evapotranspiration index（SPEI） of multi-time scales was calculated.【Result】 Whether mild or moderate drought or flood,the probability of drought is greater than that of flood,which is diametrically opposite to the Severe or extreme drought and flood;The Ezhou becomes drought-free on the whole,but the seasons vary slightly,among which spring,summer and winter become drought-free,and autumn becomes waterlogging;The drought and flood have obvious seasonal differences in Ezhou city. The summer is prone to drought,but the duration is short. The spring is prone to waterlogging and lasts a long time,（4）The precipitation has the greatest impact on drought and flood in Ezhou City,followed by evapotranspiration,which is closely related to temperature.【Conclusion】 Therefore,the SPEI is suitable for studying the evolution characteristics of drought and flood in Ezhou city,and can be used as a monitoring index of climate change and early warning.