Low-carbon development is a important way to achieve high-quality development. Carbon dioxide emissions are included in the extended C-D production function together with labor and capital，and the carbon total factor productivity （CTFP） model is derived by introducing the potential effect coefficient，that is，CTFP is equal to the weighted geometric average of labor productivity，capital productivity and carbon productivity. The calculation results show that since the 18th National Congress of the Communist Party of China，the low-carbon development of the Beijing-Tianjin-Hebei urban agglomeration has achieved remarkable results，but it is lower than that of the Yangtze River Delta and the Pearl River Delta city agglomeration. To improve the level of low-carbon development in the Beijing-Tianjin-Hebei urban agglomeration，it is necessary to pay attention to the coordination of low-carbon development in various cities，and at the same time attach great importance to the decline of capital output rate. The key to improving the level of low-carbon development is to optimize the energy structure，promote the transformation of high-carbon industries，promote the research and development of low-carbon technologies，and regulate capital behavior，so as to comprehensively improve the quality of economic growth.