Abstract: Taking theemerging service trade as the research object, this article uses the cross-border panel data to explore the impact of digital infrastructure on the sophistication of the emerging service export andits mechanisms. The findings show that digital infrastructure has significantly promoted the sophistication of the emerging service export, and this conclusion is still valid after a series of robustness and endogenous tests. The results of the mechanism test show that digital infrastructure can improve the sophistication of the emerging service export through the three channels of reducing information costs, increasing labor productivity, and increasing digital service export. The results of the heterogeneity analysis indicate that the promoting effect of digital infrastructure increases with the improvement of the local technological innovation level. Compared with the regions withhigher economic development level,the promoting effect of digital infrastructure on the regions with lower economic development level is more significant. The impact of digital infrastructure on the sub-divided emerging service industries is different; Digital infrastructure can significantly improve the export sophistication of the maintenance service, the intellectual property use fee, and the individual culture and entertainment service industry, while no significant impact can be found in the insurance and pension service, the finance service, and the telecommunications, computers and information service industry. Therefore, in the process of promoting the high-quality development of the service trade, it is necessary not only to increase the investment in the emerging service trade but also to pay attention to the important influence of digital infrastructure.

Key words: digital infrastructure, emerging service trade, service export sophistication