This paper, according to the dynamic evolution of urban compound ecological system, establishes an evaluation model and index system of compound ecological carrying capacity from ecological elastic force, supporting force, pressure and human potential, which is used to quantitatively evaluate the ecological carrying capacity of Taiyuan in 2006 to 2015, with result showing that its ecological carrying capacity index rose to 0.63 from 0.35 in the decade, reaching a higher capacity after 2012 at a slow pace in the later stage. A decreasing farmland per capita, less water resource per capita, and descending air quality, and diminishing inputs on research and environmental protection are the major constraints of sustainable development of Taiyuan. This paper applies compound system adaptability theory, and points out the uncertainty during Taiyuan's green transformation, and presents suggestions for adaptability management, offering references for policy makers to take actions during Taiyuan's urban transformation as resources-based city.