Abstract: The efficient utilization of water resources is crucial to their sustainable use, and the environmental regulations have a significant impact on resource utilization efficiency.In order to analyze the impact and especially the influencing mechanism between the environmental regulations and the water resource utilization efficiency when technological innovation is involved, this paper selects the panel data of 108 prefecture-level cities along the Changjiang Economic Belt from 2004 to 2019 as the research sample, calculates the water resource utilization efficiency of each city by using Super-SBM model, and conducts an empirical test of the impact of environmental regulations on water resource utilization efficiency from perspective of technological innovation.The results show that water resources utilization efficiency in the Changjiang Economic Belt has a relatively low efficiency.Environmental regulations remarkably promotes the water resources utilization efficiency in the area, with the lower reach being promoted the most and the middle and upper reaches coming after.Technological innovation as a mediating variable plays an intermediary effect between the environmental regulations and water resources utilization efficiency, and environmental regulations can indirectly affect water resource utilization efficiency through technological innovation.The results are expected to provide a reference for promoting water resources protection and regional high-quality development in the Changjiang Economic Belt.