The opening of the China-European railway is an important part of infrastructure connectivity in China's "One Belt, One Road" initiative. This paper analyzes the impact of the opening of the China-European railway on the quality of urban economic growth by using the opening of the China-European railway as a natural experiment. First, this study found that the opening of the China-European railway has had a significant positive impact on the quality of urban economic growth. Second, that the effect of the opening of the China-European railway on the economic growth quality of cities along the route is more obvious in cities with greater government financial support and a higher degree of marketization. Third, that the opening of the China-European railway provides a new platform for Chinese enterprises to "go global" and stimulates their development by increasing the volume and scale of outward foreign direct investment. Moreover, it has effectively promoted the quality of China's urban economic growth. Therefore, the government should play a prominent role in guiding and encouraging enterprises to take advantage of the opening of the China-European railway to conduct outward foreign direct investment.