Promoting the profound integration of “Internet+” and foreign trade is an important focus of building an advanced trading country. Based on the cross-sectional data of 286 cities in China, this paper uses robust least squares estimation, quantile regression, and cross-sectional threshold models to empirically analyze the overall effect, conditional effect, and stage characteristics of the impact of “Internet+” on China’s international trade. The research found that the improvement of China’s “Internet+” index has significantly promoted the development of foreign trade. Moreover, the increase in the “Internet+” index has a diminishing marginal effect on international trade. Furthermore, the evolution of the “Internet+” index has obvious characteristics of threshold effect on China’s foreign trade. After crossing the threshold, the “Internet+” promotion effect on international trade is greatly reduced. In terms of spatial distribution, cities in coastal areas are generally ahead of inland and border cities in the “Internet+” process, and have geographical endowment advantages in terms of location conditions. Generally speaking, the coordinated development of “Internet+” and foreign trade in most cities in China has entered a new stage. Finally, corresponding policy recommendations are put forward based on the empirical results.