Abstract: Tounderstand the impact of extreme drought events on the assurance of ecological flow in rivers and lakes, we took the extreme drought in 2022 in Changjiang River Basin as an example, the precipitation anomaly percentage from 2021 to 2023 was utilized to track the progression of the drought events, and the ecological flow guarantee rates and the percentage of non-compliant sections were employed as key indicators and conduct an in-depth analysis of the impact of drought on the achievement of ecological flow standards.Results revealed a substantial decline in ecological flow compliance condition in the basin due to the drought, with its progression not synchronizing with the meteorological drought process but exhibiting a lag of two months.Throughout the drought event, the area of ecological flow non-compliance in the Changjiang River Basin notably expanded, encompassing dozens of sub-basins, where the number of non-compliant sections reached over 50% of the total monitored sections, indicating widespread ecological flow non-compliance.The research results can reveal the spatiotemporal characteristics of the impact of drought events on ecological flow compliance in the Changjiang River Basin, providing support for river basin management.