Digital economy is a new economic format with data elements as the core and green and low-carbon characteristics，which is becoming an important engine to drive green economic transformation and high-quality development. As a prominent area of national ecological environment problems，Beijing-Tianjin-Hebei region urgently needs to tap the economic growth potential，cultivate new green economic formats and promote green and high-quality development in Beijing-Tianjin-Hebei region. On the basis of literature review，this study constructs the mechanism of digital economy affecting the efficiency of green economy from four aspects：the reset of factor structure，the birth of new formats，industrial transformation and upgrading，and pollution reduction and emission reduction. Based on the analysis of the present situation of Beijing-Tianjin-Hebei digital economy with “core-periphery” pattern and green economy efficiency with “Beijing as the core，high in the east and low in the periphery”，through the construction of spatial Dubin model，it is verified that the process of digital economy’s action on green economy efficiency has the characteristics of inverted U-shape in time dimension and spillover effect in space dimension，etc. At the same time，it is concluded that informationization，urbanization，wealth accumulation，industrial upgrading are closely related to the development of digital economy，and all of them will be. However，at present，the supporting role of government expenditure，R&D expenditure and technological innovation in Beijing-Tianjin-Hebei region for green economy is still insufficient，and the industrial linkage pattern of digital economy has not yet been formed. We should develop the digital economy in an orderly manner，cultivate leading enterprises in the digital economy，build the Beijing-Tianjin-Hebei digital economy chain，increase the investment in green innovation research and development，and expand the emission reduction effect of the digital economy，etc.