[Objective] The comprehensive development quality of 102 county-level units in Shanxi Province from 2012 to 2023 was scientifically evaluated in order to provide a scientific basis for regional high-quality development and the optimization of administrative divisions. [Methods] Based on the core connotations of new-type urbanization and coordinated development, an evaluation framework for comprehensive development quality was constructed from the three-dimensional perspective of ‘society-landscape-ecology'. Theil index, exploratory spatiotemporal data analysis, and obstacle degree model were comprehensively applied to analyze the spatiotemporal patterns of comprehensive development quality in the study area and to diagnose obstacle factors. [Results]① The comprehensive development quality of counties in Shanxi Province showed a slow upward trend, with an average annual growth rate of 1.28%. Spatially, it exhibited a pattern of ‘large dispersion with small concentration', with high-level areas clustered in the central region and southeastern Shanxi Province, and low-level areas distributed in the Yuncheng Basin.② Overall differences showed a fluctuating convergence trend, but 62.75% of the differences originated from internal prefecture-level cities, with intra-city disparities in Jincheng, Lüliang, and Changzhi showing an expanding trend.③ Global spatial correlation was significant but continuously weakened, and the local spatial structure exhibited strong characteristics of ‘path dependence' and ‘spatial lockin'.④ Social development quality was the most constraining dimension at present, with the total volume of postal and telecommunications services, total profits of industrial enterprises above designated size, and fixed-asset investment per unit of land area identified as the three core obstacle factors. Meanwhile, the constraining effects of the ecosystem and landscape pattern quality were gradually becoming apparent. [Conclusion] The comprehensive development quality of counties in Shanxi Province has improved, but it still faces challenges such as internal imbalances, spatial lock-in, and multidimensional constraints. In the future, socio-economic development and ecological protection should be coordinated to achieve three-dimensional synergistic enhancement.