Abstract: In the process of global urbanization, the real estate industry has experienced a series of fluctuations that have affected its sustainable and healthy development, mostly owing to the reduced housing affordability for residents caused by non-synergy of population-land-industry urbanization (PLIU). However, relatively few studies have examined the impact of urbanization on urban residents’ housing affordability from a PLIU synergy perspective. This paper analyzes spatial pattern evolution of urban residents’ housing affordability from 2005 to 2020 by constructing an evaluation model for measuring urban residents’ housing affordability. Through the innovative ‘cube’ method for measuring PLIU synergy, based on Spatial Durbin Model (SDM) and Geographically and Temporally Weighted Regression (GTWR), we analyze the impact of urbanization on urban residents’ housing affordability. The main conclusions are presented as follows: first, the overall urban residents’ housing affordability in China (excluding Hong Kong, Macao, and Taiwan) has shown an upward trend, with spatial ‘zonal differences’ and ‘hierarchical differences’. Second, the urbanization process has a significant negative effect on urban residents’ housing affordability, and the PLIU construct is not synergistic, with population and industry urbanization lagging behind land urbanization. Third, spatial heterogeneity is evident in the impact of urbanization on housing affordability, especially in urban agglomerations. The core of the evolution of urban residents’ housing affordability lies in the matching of population, land, and industrial urbanization, and the synergy of the three developments. In the Yangtze River Delta urban agglomeration and Urban Agglomeration of the Middle Reaches of the Yangtze River, the advancement of urbanization has a positive effect on urban residents’ housing affordability, and PLIU is synergistic, while in the Beijing-Tianjin-Hebei urban agglomeration, Pearl River Delta urban agglomeration, and Chengdu-Chongqing urban agglomeration, the effect is negative and PLIU is not synergistic, and with the former two, population urbanization is ahead of the others, whereas land urbanization is ahead of the others in the latter. This paper provides a reasonable explanation for the aforementioned results, revealing the mechanisms of how urbanization affects housing affordability, and can serve as a valuable reference for global research on housing affordability, holding significant importance.