Abstract: Based on the data of Beijing-Tianjin-Hebei urban agglomeration from 2003 to 2020, the coupling coordination degree, spatial Durbin and spatial-temporal geographical weighted regression models were used to explore the spatial and temporal characteristics of the synergistic effect of pollution reduction and carbon reduction in the urban agglomeration and the heterogeneity of its influencing factors. The study showed that carbon emissions grew rapidly from the 10th to the 11th Five-year Plan periods, and then slowed down after the 12th Five-year Plan period. The emission of atmospheric pollutants reached its peak during the 12th Five-year Plan period, and the emission reduction effect during the 13th Five-year Plan period was significant. During the study period, the level of pollution and carbon reduction coupling and coordination showed three phases of fluctuating increase, namely, slow increase, hovering exploration and steady increase; the energy consumption intensity and total energy consumption were the core factors directly affecting the level of pollution and carbon reduction coupling and coordination in the cities. The urbanization rate, real GDP per capita, industrial structure, the amount of foreign investment utilized and the proportion of science and technology expenditure were the core factors affecting the level of pollution and carbon reduction coupling and coordination by affecting energy consumption, and all factors showed spatial and temporal heterogeneity. Finally, optimized countermeasures were proposed in terms of promoting collaborative control of regional pollution reduction and carbon reduction, strengthening differentiated collaborative emission reduction strategies for key cities and key industries, promoting energy restructuring, and focusing on green technology innovation and green financial support.