High-speed railways have become an important driving force influencing the development of urban trade due to their unique technical and economic characteristics. However, further exploration is needed to explore how it affects urban import and export trade. Through the 2006-2018 panel data of 56 cities with three levels of openness, the double difference model (DID) is used to conduct empirical research to analyze the impact of high-speed rail on urban trade development. The conclusion shows that: high-speed rail has no significant impact on overall urban trade development; high-speed rail has a significant role in promoting trade development in cities with a lower degree of openness; high-speed rail mainly promotes the development of urban import trade to improve the overall level of urban trade.