In the context of accelerating the construction of a new development pattern, digital economy actively promotes optimization and upgrading of the service industry, which is of great significance to help the construction of a modern economic system and promote high-quality economic development.From 2014 to 2020 provincial panel data of our country is used to study the impact mechanism of digital economy on optimization and upgrading of service industry.It is found that digital economy helps to promote optimization and upgrading of service industry,technological innovation plays a part of the intermediary effect in the influence process,and the level of marketization positively regulates the direct effect and intermediary effect of the influence mechanism.