The equalization of basic public cultural services is the goal and implementation path of building a moderately prosperous society in an all-round way and realizing common prosperity. The paper takes the supply of basic public cultural services in 31 provinces and regions in the Mainland as the research object during the period from 2011 to 2019. Through statistical analysis and empirical analysis of Theil index， it verifies and measures the degree of non-equalization of supply between urban and rural areas and between regions. Analysis of the causes of non-equalization mainly include the imbalance of urban and rural cultural funding， the absence and dislocation of public cultural service supply and so on. It suggests the necessity to build a sustainable capital investment system for the equalization of public cultural services， and to improve the overall scale and quality of the supply side of cultural resources. These are of great significance for guaranteeing and realizing the cultural rights of all citizens.