Common prosperity is an important feature of Chinese path to modernization, and is also the original intention and mission of the CPC. The advancement of human capital structure is an important influencing factor in achieving the goal of common prosperity. This study takes the advancement of human capital structure as the research entry point, and combines provincial level data from 2005 to 2022 to empirically test the impact of the advancement of human capital structure on the level of common prosperity and its underlying mechanism. Research has found that the upgrading of human capital structure has a significant promoting effect on the improvement of China’s common prosperity level; Heterogeneity analysis reveals that the upgrading of human capital structure has a significant heterogeneity in its impact on provinces with different regions, financial resources, and technological levels; Mechanism testing also found that the upgrading of human capital structure mainly helps to improve the level of common prosperity through three paths: promoting the improvement of total factor productivity, enhancing technological innovation capabilities, and promoting labor force transfer. The research results provide a new perspective for understanding the role of advanced human capital structure in promoting China’s common prosperity, and provide empirical evidence support for the achievement of China’s common prosperity goals.