The policy of “county administrated by province” is crucial to promoting the equalization of basic public services. By collecting Guangdong’s 2009-2020 county-level public services’ expenditure data, time-varying DID method is applied to identify the policy effect of the policy on equalization of basic public services. This paper finds that the policy of direct provincial administration of counties significantly improves the fiscal revenue of pilot counties, which in turn promotes the level of equalization of public services with strong geographical and productive attributes. But the policy does not significantly affect public services with weaker geographical and productive attributes. Based on these conclusions, the reform of direct provincial administration of counties should continue to be promoted, same as to improve the division of public service authority and expenditure responsibilities.