The core of the goal of common prosperity is to increase the income of residents and narrow the income gap between residents. The improvement of human capital level can increase the income of workers.As an important index of income distribution, labor income share is conducive to improving the inequality of primary distribution, narrowing the income gap, and promoting the realization of the goal of common prosperity. By using the data of 30 provinces in China from 2011 to 2021, the influence of human capital on common prosperity and the role of labor income share between them was empirically analyzed by using fixed effect and intermediary effect models. It is found that the improvement of human capital level can promote common prosperity, and this conclusion is still valid after a series of robustness tests. The intermediary effect analysis shows that the labor income share plays an intermediary role in the influence of human capital on common prosperity. Heterogeneity analysis shows that the role of human capital in promoting common prosperity is more obvious in the east and the regions with large economic scale.