Abstract: Ecological efficiency can reflect the core connotation of sustainable and green development, and is a research hotspot for achieving ecological civilization construction and the development of new quality productivity forces. Taking the cities in the middle reaches of the Yellow River as the research object, we used methods such as the undesired output super-efficiency SBM model, ESDA and geographical detector model to analyze the spatiotemporal evolution pattern and influencing factors of ecological efficiency of urban agglomerations in the middle reaches of the Yellow River, from the perspective of new quality productivity forces development from 2010 to 2020. The results showed that: (1) The ecological efficiency of the urban agglomeration in the middle reaches of the Yellow River showed an overall fluctuating upward trend, with the ecological efficiency value increasing from 0.506 to 0.804. The Theil index of the entire middle reaches of the Yellow River decreased from 0.197 to 0.098, and the overall polarization phenomenon of regional ecological efficiency was weakening, with absolute differences continuously narrowing, but the internal differences in ecological efficiency among urban agglomerations were still significant. (2) The ecological efficiency of the urban agglomeration in the middle reaches of the Yellow River had shifted from the initial spatial distribution pattern of high in the northwest and low in the southeast to a "multi-point belt" spatial structure with Hohhot, Zhengzhou, Taiyuan, and Xi'an as the core cities. The role of provincial capital cities in radiating the surrounding urban space was more significant. (3) The ecological efficiency of the urban agglomeration in the middle reaches of the Yellow River had not yet shown significant spatial autocorrelation in spatial distribution. From the perspective of local spatial autocorrelation, except for 2010 when the middle reaches of the Yellow River showed local spatial correlation, the ecological efficiency did not form agglomeration characteristics in local space at other times. (4) As for the influencing factors, from the perspective of new quality productivity forces, the development of ecological efficiency in the middle reaches of the Yellow River Basin urban agglomeration was mainly influenced by policy support, industrial structure adjustment, economic development, and technological innovation. Therefore, in the future, we need to accelerate the transformation of the economic development model in the middle reaches of the Yellow River, adjust the industrial structure, promote technological innovation, and achieve ecological protection and high-quality development in the region.