Abstract: Enhancing energy efficiency is a crucial pathway to achieving high-quality economic development and the “dual carbon” goals. This study utilized a panel dataset of 262 prefecture-level cities from 2008 to 2022 to empirically examine the impact of regional integration policies on urban energy efficiency. The findings indicated that: (1) The implementation of the Yangtze River Economic Belt development strategy significantly improved urban energy efficiency. This conclusion remained robust after a series of robustness tests. (2) The heterogeneous analysis revealed that the strategy has a more significant effect on the energy efficiency of non-resource-based cities,riverside cities,and non-traditional industrial cities. The effect on energy efficiency improvement was significant,but varied across different urban agglomerations within the Yangtze River Economic Belt. (3) The implementation of the strategy promoted urban energy efficiency through the flow of innovative factors,green technological innovation,and the integration of infrastructure.