Taking 57 prefecture-level cities in the Yellow River basin as a research area, this study evaluates the coupling coordination level of the water–energy–carbon (WEC) system in the Yellow River basin from 2012 to 2021 and explores the driving factors of coupling coordinated development. The study revealed that: (1) the development level of the three subsystems all showed an upward trend. The development level of the carbon system exhibited the highest level. The development index of the carbon and energy systems rose steadily, whereas the development index of the water system fluctuated considerably during the research period, although the magnitude of the fluctuation gradually slowed down. (2) The coupling coordination degree displayed a distribution characteristic of “high in the east and low in the west, high in the south and low in the north”. While the coupling coordination degree improved year by year, the spatial heterogeneity gradually increased. (3) The coupling coordination degree presented a positive correlation, and the agglomeration level was dominated by “high-high” and “low-low” agglomeration types. The “high-high” agglomeration area had a certain degree of spatial mobility, while the “low-low” agglomeration areas showed a tendency for spreading towards the middle reaches of the Yellow River basin. (4) Technological innovation, and the economic basis, had a significant positive impact on the coupling coordinated development, while the industrial structure bias showed a clear inhibitory effect. The positive role of opening up is not yet significant. Meanwhile, the indirect effect of each driving factor was greater than the direct effect.

In order to achieve China’s carbon peaking and carbon neutrality (double carbon) targets and to advance ecological conservation and high-quality development in the Yellow River Basin, it is essential that China reduces its energy intensity and increases its energy efficiency. This research developed an evaluation index system for energy efficiency and green development in the Yellow River Basin based on panel data collected from 64 of its prefecture-level cities and covering the period from 2011 to 2020. Each city’s energy efficiency and green development level index was calculated, and was analyzed together with the characteristics of its spatial pattern progression. The STIRPAT model was then used to investigate the influence mechanism of energy efficiency on green development. The final step in the analysis was to assess the process by which technical innovation influences the rise in energy efficiency from a green development point of view. The findings of this study indicate that: (1) There was a marked improvement in energy efficiency and green development levels across the Yellow River Basin over the study period of 2011 to 2020, but there are notable disparities among prefecture-level cities, with higher levels found in capital cities and cities in the lower reaches of the basin. (2) The improvement in energy efficiency has had a positive impact on the transition to green development, with factors such as human capital, urbanization levels, and the upgrading of industrial structures contributing significantly, while the level of foreign direct investment has had a limited impact. (3) Technological innovation plays a partial role in mediating the relationship between energy efficiency and green development in the Yellow River Basin, and passes the single-threshold test. When technological innovation surpasses the threshold value, the effect of energy efficiency on green development is significantly strengthened. This study indicates that improving energy efficiency, stimulating emerging industries, and enhancing technological innovation capabilities can significantly promote transformative green and high quality development in the Yellow River Basin of China.