Green development is a model of coordinated and sustainable economic growth and social development. Improving the level of green coordinated development in a region is a basic requirement for urban sustainable development. The Beijing-Tianjin-Hebei region is an important core urban agglomeration for economic development in northern China.Taking the Beijing-Tianjin-Hebei region as an example, this study uses environmental data from 2011 to 2020 to assess the level of green coordinated development between industrial upgrading and the ecological environment based on the theory of coordinated development. And use the system dynamics method to explore the important factors affecting the green coordination in the study area. The main results are as follows: 1. During the research period, the degree of green coordination in the study area has been continuously improved, the growth trend of industrial development is more obvious, and the improvement of the ecological environment is not obvious.2.The gap between Beijing, Tianjin, and Hebei has been further widened, Beijing is at a high level of coordination, while Tianjin and Hebei are at a low level of coordination.3.Reducing energy consumption and increasing the labor force in the tertiary industry are both important factors affecting the level of green coordinated development in a region, Moreover, the reduction in energy consumption has a more significant effect on improving the coordination level.