Abstract: This paper selects 16 prefecture-level cities within Chengdu-Chongqing economic region，covering the time span from 2006 to 2020，as the research subjects.It investigates the temporal and spatial coordination between population and economy，builds a spatial panel model to explore the impact mechanisms of various driving factors on economic development，analyzes the quality of social development，and examines the spatial distribution patterns of urban cluster structure development.Our empirical results indicate：①the overall population development coordination index exhibits a fluctuating distribution pattern，in 2020，the coupling coordination degree of most cities was greater than 0.8；②only per capita GDP，and the level of openness to the outside world have significant effects on its economic index；③ the spatial pattern of social development shows a spatial differentiation of“fast development at its core area，under-development at its central and northeast area”；④the quality of urban size has transformed from extreme concentration（D＝2.05）in 2006 to relative equilibrium （D＝1.08）in 2020，with an overall scale characterized by a radiating imbalanced structure centered around Chengdu and Chongqing.