In order to limit urban sprawl, many cities around the world have developed green belts . A large number of studies have used Landsat remote sensing data with a spatial resolution of 30 m to assess the construction of green barriers; however, the 30 m resolution makes it difficult to accurately quantify the fragmented green space patches and their dynamic changes in the city, and it is not possible to accurately assess the ecological construction of green barriers. Therefore, this study assessed the evolution of the ecological pattern of the first and second green compartments in Beijing from 2015 to 2021 using 2-m high resolution remote sensing data. The study showed that (1) the ecological construction of the green compartment area in Beijing from 2015 to 2021 was remarkable. The total area of green space within the green compartment increased by 54 km2, the density of patches decreased, and the area of patches increased; in contrast, the area of green space in the area surrounding the green compartment decreased by 1.77 km2, a large number of small green patches disappeared, and large green patches were gradually fragmented. (2) The ecological construction of green partitions mainly focuses on the second green partition, which shows that 87% of the new green space is in the second green partition, and the improvement of green space patch area and connectivity is more significant, while the first green partition is surrounded by construction land, and the space for incremental green space is limited in the internal green space. (3) The construction of green partitions has increased the proportion and connectivity of green space, which has played an important role in the disorderly expansion of the city in the form of ‘big pie’. In the future, we can focus on the connectivity of low green space patches within the green compartments, and create urban green compartments with more complete and continuous green space. In recent years, with the acceleration of urbanization, the contradiction between urban expansion and ecological protection has become increasingly. prominent Green belts, as an important means of curbing urban sprawl, have been widely concerned. In this context, the research on the ecological pattern evolution of green belts has also become a hot topic in the field of ecology and urban planning. The study of Beijing's green belt ecological pattern evolution using high-resolution remote sensing data provides a new perspective and method for this field. The results of this study not only show the significant achievements of Beijing's green belt construction, but also reveal the existing problems and challenges. For example, the decrease in green space area and the fragmentation of green patches in the area surrounding the green belt indicate that more attention should be paid to the protection and restoration of green space in this area in the future. At the same time, the limited space for increasing green space in the first green belt also suggests that it is necessary to explore more innovative ecological construction models and strategies. Overall, this study provides valuable references and suggestions for the sustainable development of urban ecology and the construction of green belts.