On the perspective of complex network, takeing the ecological efficiency of urban agglomerations as the research object, the impact of S T investment and network characteristics on ecological efficiency has been explored. Using panel data of 30 cities from 2003 to 2017 to measure the ecological efficiency of the Central Plains urban agglomeration, the characteristics of network nodes are obtained. Applying the geographic gravity model, the eco-affiliated network has been constructed. Finally, the impact of S T investment and network characteristics on ecological efficiency is analyzed. The results show that: (1) the overall ecological efficiency of the Central Plains urban agglomeration shows a continuous upward trend, and the spatial distribution of "one body, two wings"; the level of urban ecological efficiency has significant individual differences, while the gaps continue to expand. (2) Connectivity of urban agglomeration network is high-level, and the overall network density first rises and then decreases; Zhengzhou-Jiaozuo-Luoyang-Xinxiang constitute the core pole of urban agglomeration, cities which are close to the core area have a high ecological level; and there is obvious difference among cities. (3) S T investment and closeness have significant positive impacts on ecological efficiency, while they interact with each other and lead to positive effects; industrial structure and urbanization rate also have significant positive impacts on ecological efficiency, while FDI has no significant impact.