Abstract: Water resource supply-demand tensions in China's semi-arid urban areas have become a critical bottleneck constraining sustainable urban development．Addressing this challenge, Tianshui City in Gansu Province was taken as an example to construct a comprehensive evaluation system integrating "water resources-society-economy-ecology" with 17 assessment indicators．A theoretical reference for sustainable water resource management in semi-arid cities of northwest China was provided．CRITIC-entropy weight method was used to determine index weights, while PCA and TOPSIS models assessed water resources carrying capacity levels, and obstacle degree model was used to identify key limiting factors．Results showed that from 2014 to 2023, top three weights of water resources carrying capacity indexes in Tianshui City were population density, ecological environment water use rate, and water consumption per 10000 yuan of industrial added value．Comprehensive evaluation values obtained from both methods showed an upward trend, with evaluation grade improving from poor to moderate．Within water resources subsystem, per capita GDP, water consumption per 10000 yuan of industrial added value, and population density exhibited the most significant impedance, constituting main constraint bottlenecks．