Promoting coordinated and environmentally sustainable development of the Chinese economy is one of the primary tasks at the moment, as well as one of the sustainable development goals of the United Nations. The Resource-saving and Environment-friendly Society (RES) has created a pilot promotion policy aimed at China, with the goal of supporting the sustainable development of economic production activities while preserving natural ecosystems. In this investigation, we used the global Malmquist–Luenberger index with a slack-based measure of the directional distance function to calculate the industrial green total factor productivity (IGTFP) of 105 prefecture-level cities along the Yangtze River from 2004 to 2019; IGTFP was used as a proxy for sustainable development. Then, by considering the RES construction as a quasi-natural experiment, we used propensity score matching difference-in-differences (PSM-DID) to determine the effect of RES construction on sustainable development of the Yangtze River economic belt. We also employed the mediating effect model and triple difference (DDD) model to further analyze the mechanisms underlying the heterogeneous impacts of different urban characteristics. The results revealed three key findings. (1) According to the IGTFP calculation results, RES construction can effectively promote green technological progress while inhibiting green technological efficiency. (2) After carrying out a series of robustness tests, we found that RES construction increased the IGTFP of pilot cities by 4%, indicating that RES construction can significantly promote the sustainable development of pilot cities along the Yangtze River. (3) The results of the mechanism analysis showed that RES construction had a significantly positive impact on sustainable development through technological innovation, human capital, energy conservation, and emission control. In terms of different urban characteristics, the RES construction promoted sustainable development in first-tier cities, second-tier cities, and resource-based cities. We summarized the practical experience of the RES construction as a typical pilot promotion policy. It provides an empirical basis for planning the construction of eco-friendly urban areas in the 21st century and responding to the international community’s sustainable development goals from a Chinese perspective.