Abstract: It constructs a measurement system for the development efficiency of the science and technology service industry in the Yellow River Basin based on the three-stage Data Envelopment Analysis (DEA) model. It measures and conducts a spatio-temporal evolution analysis of the development efficiency of the science and technology service industry across the nine provinces/regions in the Yellow River Basin from 2014 to 2023. The findings indicate that environmental factors lead to an overestimation of actual efficiency, with low scale efficiency being the core constraint. Regional efficiency differentiation has intensified: Shandong Province, Henan Province, Sichuan Province, and Shaanxi Province have consistently remained at the efficiency frontier, while the other five provinces/regions lag behind due to constraints imposed by scale efficiency. Pure technical efficiency demonstrates strong resilience, yet technological upgrading has failed to break through the bottleneck of diseconomies of scale. To advance the science and technology service industry in the Yellow River Basin, institutional innovation is required to unblock the "environment-technology-scale" transmission chain, thereby driving the systematic reconstruction of efficiency across the entire basin.