The integrated application of new digital infrastructure in the ecological field provides solid support for ecological protection and highquality development in the Yellow River Basin.Based on the panel data from 97 cities along the Yellow River Basin from 2013 to 2020, this paper systematically verified the impact of new digital infrastructure on urban ecological efficiency in the Yellow River Basin and its mechanism from the perspective of spatial spillover.The results show that the construction of new digital infrastructure and its spatial spillover effects have significantly improved urban ecological efficiency in the Yellow River Basin, and this conclusion remains valid after a series of robustness tests.The positive spatial spillover effect of new digital infrastructure on urban ecological efficiency in the Yellow River basin is significant in the range of 900 km, but will disappear in the range of 1200 km and above.Further research found that the new digital infrastructure mainly promotes the ecological efficiency of the city and neighboring cities through green technology innovation, optimal allocation of resources and industrial structure upgrading.The positive spillover effect of the new digital infrastructure on the ecological efficiency of the Yellow River Basin is significant in the middle and lower reaches, urban agglomeration and nonresourcebased cities.

digital economy; new digital infrastructure; Yellow River Basin; ecological efficiency; spatial spillover effect