With the in-depth advancement of the Beijing–Tianjin–Hebei coordinated development strategy, establishing a new mechanism for coordinated development in regional coordinated development is an important measure to realize the green, low-carbon and sustainable development of the Beijing–Tianjin–Hebei urban agglomeration. At present, there are significant differences in carbon emission intensity among different cities in the Beijing–Tianjin–Hebei urban agglomeration, which poses a significant obstacle to the synergistic development goals of the Beijing–Tianjin–Hebei region. Therefore, studying the carbon emissions of the Beijing–Tianjin–Hebei urban agglomeration is of great significance for achieving synergistic development in the Beijing–Tianjin–Hebei region and achieving China’s dual carbon goals. Based on the above practical background, this study focuses on the carbon emissions of the Beijing–Tianjin–Hebei urban agglomeration, using the gravity model, the social network analysis method, and the synergistic effects of carbon emission reductions model to analyze the general characteristics of the carbon emission spatial network, individual characteristics of the carbon emission spatial network, and synergistic effects of carbon emission reduction in the Beijing–Tianjin–Hebei urban agglomeration. The study found that the carbon emission spatial network of the Beijing–Tianjin–Hebei urban agglomeration presents a typical core–periphery structure. From the perspective of the general characteristics of the spatial network, the ranking structure of carbon emissions among cities in Beijing–Tianjin–Hebei is strict, and the network stability is good; from the perspective of individual characteristics of the spatial network, Beijing and Tianjin are the centers of the carbon emission spatial network of the Beijing–Tianjin–Hebei urban agglomeration, playing an important role of “betweenness” and “bridge”, while cities in Hebei Province are in a weak position in this regard. From the perspective of the measurement result of synergistic effects of carbon emission reduction, there is significant room for improvement in the synergistic effects of carbon emission reductions in the Beijing–Tianjin–Hebei urban agglomeration, and there are significant differences in the synergistic effects of carbon emission reduction among various cities. In general, at this stage, the core–periphery structure of the spatial network of carbon emissions in the Beijing–Tianjin–Hebei urban agglomeration is still solid, and the synergistic effects of carbon emission reduction between cities are weak. Establishing a sound synergistic mechanism of regional carbon emission reduction is the key to solving the carbon emission problem of the Beijing–Tianjin–Hebei urban agglomeration. Therefore, this study proposes countermeasures and suggestions to improve the synergistic mechanism of the reduction in carbon emissions in the Beijing–Tianjin–Hebei urban agglomeration from three levels—the formation layer, the implementation layer, and the guarantee layer—in order to promote synergistic emission reduction, ecological and environmental governance, and sustainable development of Beijing–Tianjin–Hebei urban agglomeration.