Vegetation is an important part of terrestrial ecosystem and is vulnerable to extreme climate events. It is of great significance to explore the spatio-temporal evolution and dynamic response relationship between extreme climate events and vegetation for scientific response to climate anomalies and prevention of natural disasters. Therefore, the RClimDex, trend analysis and detrended fluctuation analysis were used to analyze the spatio-temporal evolution of extreme climate and NDVI in the Huaihe River Basin from 1998 to 2019, and discuss their causes and future variation tendency as well as clarify the response of NDVI to extreme climate. The results demonstrate that the NDVI shows an increasing tendency with an increase of 0.002 5 a^-1 from 1998 to 2019. Among the extreme climate indices, warm temperature indices showed an increasing tendency, while the cold temperature indices and precipitation indices (except RX1day) showed a decreasing tendency. The distribution of NDVI in the Huaihe River Basin was closely related to the distribution of urbanization in the region. The NDVI has a lag response of about one month to extreme climate and will continue to rise. The annual variation of the NDVI is closely related to natural and human factors, and the intra-annual variation of the NDVI is mainly affected by the growth rhythm of crops in the cultivated land.