This report constructs interregional collaborative governance of carbon reduction indicator and divides the indicator into active synergistic carbon reduction and passive synergistic carbon reduction based on the differences in urban route choice behavior. Taking the Beijing-Tianjin-Hebei region as the object of research，the study thoroughly explores the driving effect and mechanism of the digital economy on interregional collaborative governance of carbon reduction. The study shows that the digital economy significantly improves the efficiency of interregional collaborative governance of carbon reduction，especially in the passive synergistic carbon reduction，showing the differentiated impacts on different synergistic carbon reduction methods in specific types of cities. The report recommends promoting the development of the digital economy，strengthening regional synergistic carbon reduction and implementing differentiated development strategies according to local conditions.