Many cities across the country connect hub-airports with rail transit for industrial layout, taking advantage of air-rail hub in urban economic externalities. The air-rail hub is a comprehensive transportation hub formed by connecting the airport and the high-speed railway station, which improves the efficiency of transportation and has significant transportation value. In the process of promoting urban industrial development, the air-rail hub has significant externalities. The industrial layout has been continuously optimized, the industrial structure has become more reasonable, and the industrial agglomeration has been continuously enhanced. The results of internalization are population concentration, industrial agglomeration of knowledge economy, and accelerated prosperity of urban economic growth. Taking Shanghai Hongqiao airport as an example, it is found that the air-rail hub has formed a spatial-time economic scope with a radius of 3.5 kilometers under the interaction of the airport and the high-speed rail industry circles. Through a reasonable industrial layout, it is linked with Hongqiao Business District, thus forming a successful experience of the port-industry-city integrated development. The government should actively carry out the industrial layout and policy support, reasonably position the city"s energy level, attach importance to the industrial cluster in the industrial chain, and promote the internalization of the externalities of the air rail hub.