The governments of most countries are striving to coordinate residents’ housing demands with the supply of land to achieve high-quality urbanization and improve residents’ welfare. Based on the panel data of all Chinese provinces from 2010 to 2017, this study obtains 248 observations. It uses the coupling coordination degree, the Mann–Kendall trend test, and spatial autocorrelation methods to analyze the temporal and spatial variation of the coordination degree of population urbanization and affordable housing land supply. The study aims to clarify the temporal trend further and identify the spatial mismatch of affordable housing land resource allocation and apply a panel fixed model to determine its driving factors. The regional differentiation of the coordinated development level of population urbanization and affordable housing land in China’s provinces is apparent. The overall spatial distribution characteristics of coordination are opposite to the development of its economic level. The Mann–Kendall trend test indicated that the coupling coordination degree had a significant upward trend nationwide. Moreover, the coupling coordination degree shows a strong positive global spatial correlation. The local spatial agglomeration characteristics of the coordination are significant and primarily manifested in high and low–low agglomeration. A negative correlation exists between the degree of coupling coordination and the dependence of local governments on land finance and housing prices.