In the current complex international environment, promoting high-quality development (HQD) of the urban economy plays a crucial role in enhancing the ability of China’s urban economies to respond to international challenges. Water resources (WRE) and carbon emissions (CEM) are two important subsystems that constrain the HQD of the urban economy. Studying the coupled, coordinated, and synergistic relationships between urban economic quality development and these subsystems is crucial for promoting the HQD in the urban economy. Taking Xi’an as an example, this thesis uses the entropy weight TOPSIS method and the coupling coordination evaluation model to assess the development levels of Xi’an’s urban economy, WRE support, and CEM, and the coupling, coordination, and systemic relationships among them. The findings are as follows: (1) The comprehensive development levels of the subsystems of urban economic development quality, water resource support, and CEM in Xi’an show a continually improving situation. (2) The coupling state between Xi’an’s urban economic development quality subsystem and other two subsystems show a trend of initial improvement, followed by a decrease, and then stabilization. (3) The coordination state between Xi’an’s urban economic development quality subsystem and other two subsystems remain highly consistent, displaying a wave-like rising trend. (4) The synchronous development pace of Xi’an’s urban economic development quality subsystem with other two subsystems is generally aligned. By studying the issues related to HQD of urban economy under the dual constraints of “carbon” and “water”, this research not only enriches the theoretical understanding of HQD of urban economy but also provides useful references for promoting high-quality economic development in Xi’an and other cities.