Based on the fairness and efficiency dimensions, the index system was constructed, and the entropy method was used to measure the level of common prosperity of China's provinces from 2011 to 2021, analyze its spatial autocorrelation, describe its distribution dynamics through the kernel density estimation method, and analyze its spatial differences using Dagum Gini coefficient. It is found that the level of common prosperity across the country and the four major regions has significantly improved, with the western region experiencing the largest increase. During the inspection period, the national spatial combined effect is significant. The problem of uneven development of common prosperity in the eastern region is most prominent. The regional differences are showing a narrowing trend, but they are still the main source of overall differences.