Abstract: Economic flow can reflect the intensity of economic connection between cities and the dependence of economy among cities, which is of great significance for the analysis of economic connection among cities in urban agglomeration. Based on this, this paper, with the help of the gravity model, combined with the perspective of economic flow, calculates the economic flow intensity of each city in the Beijing-Tianjin-Hebei Urban Agglomeration from 2014 to 2019 and the economic membership degree of each city to the other two cities. Combined with the analysis of the development process of Beijing-Tianjin-Hebei, it finds that the current collaborative development of Beijing-Tianjin-Hebei is more limited. The collaborative development of "Beijing-Tianjin-Langfang" needs to be solved step by step, from "Beijing-Tianjin-Langfang" to "Beijing-Tianjin-Xiongan" and then to "Beijing-Tianjin-Hebei". To solve this problem, we need to start with economy, transportation, people's livelihood and industry. Beijing should play a radiating role in promoting the coordinated development of Beijing, Tianjin and Hebei, improving the transportation infrastructure, building a regional economic network, improving the happiness index of residents, promoting the transfer of population between cities, and promoting the coordinated transformation of Beijing, Tianjin and Hebei industries.