Based on the coupling system of water resources, water environment, and socio-economy, a comprehensive evaluation index system of water environmental carrying capacity(WECC) of the Yangtze River Economic Belt (YREB)was constructed. The entropy-TOPSIS method was used to measure WECC from 2010 to 2019, and the standard deviation ellipse, global Moran's index, and Geodetector method were combined to explore the spatial-temporal evolution pattern and main driving factors of WECC. Results show that WECC presents a descending tremd in an order of downstream, upstream, and midstream of the YREB , with top three provinces (municipalities) of WECC in the YREB being Shanghai, Zhejiang, and Chongqing; there is no provincial spatial dependence of WECC in the YREB, and the standard deviation ellipse of WECC presents a stable east-west spatial distribution pattern and a trend of movement in the southwest direction, with its geographical center located between Yueyang City in Hunan Province and Jingzhou City in Hubei Province; the primary driving factor of WECC is water consumption per ten thousand CNY of GDP, the socio-economy subsystem has the greatest influence on WECC, followed by the water environment subsystem and water resources subsystem, and the main driving factors of different regions have significant spatial heterogeneity.