Investigating the characteristics of water-carbon variables in terrestrial ecosystems and their drivers was critical for understanding ecosystem water-carbon cycles. This article adopted spatiotemporal analysis and a spatial correlation interaction detector (IDSA) model, integrating MODIS and ERA5-Land data with land cover and vegetation indices to analyze the spatiotemporal patterns (2001-2020) of evapotranspiration (ET), gross primary productivity (GPP), and water use efficiency (WUE) in the Yellow River Basin. The results showed that: (1) In terms of time, GPP and ET in the Yellow River Basin significantly increased from 2001 to 2020, with multi-year averages of 462.95 g C m?2 and 349.34 mm, respectively. The rate of increase varied depending on the land cover type, and WUE showed no significant decreasing trend, with a multi-year average of 1.36 g Cmm?1 m?2. (2) Spatially, GPP and WUE exhibited a decreasing trend from east to west, with high GPP values (>805.18 g C mm?1 m?2 ) accounting for 9.90% and low GPP values (<330.55 g C m?2) accounting for 35.87%; The high-value area of WUE (>1.76 g Cmm?1 m?2) accounted for 21.90%, while the low value area (<0.79 g C mm?1 m?2) accounted for 11.48%. ET showed a decreasing trend with more in the south and less in the north, with high-value areas (>461.71 mm) mainly located in the source and lower middle reaches of the Yellow River, and low value areas (<243.70 mm) in the northwest of the Loess Plateau. (3) Different land use patterns had a prominent impact on water carbon cycling, with forests showing significant advantages in ET, GPP, and WUE, with mean values of 441.20 mm, 737.90 g C·mm?1 m?2, and 1.69 g C mm?1 m?2, respectively. (4) Vegetation factors (FVC, LAI) were the main influencing factors of ET and GPP changes at the watershed scale and different land cover types scale, while meteorological factors, especially temperature (T) and precipitation (Prec), were the main influencing factors of WUE. In terms of the interaction of influencing factors, the explanatory power of the interaction of multiple influencing factors on WUE changes was significantly enhanced. The spatial fuzzy superposition results of multi factor interactions showed that vegetation factors played a dominant role in the WUE changes in the upper and middle reaches of the Yellow River Basin, while meteorological factors played a dominant role in the WUE changes in the middle and lower reaches of the Yellow River Basin. The research results could provide support for ecological protection and restoration in the Yellow River Basin.