In order to implement the new requirements of the "four persistence, three support and two forefront" proposed by general secretary Xi Jinping to Guangdong Province, the effective ways to lead the realization of the modernization of the province are explored. In this study, the relevant theories of modernization are referred and the relevant experience of the developed countries and advanced areas is summarized, and seven evaluative dimensions for the city modernization are defined, namely economy, spatial form, social development, culture, ecological environment, infrastructure and urban governance, and 50 indexes are selected from the seven dimensions to construct a set of quantifiable modern city index system. And on this basis, the existing gaps and major problems of the basic realization of the modernization in the province at this stage are assessed, and the corresponding countermeasures and suggestions for the construction of modern cities in Guangdong Province are put forward.