Abstract: The routine transfer of inter-project learning of air pollution control in Beijing-Tianjin-Hebei region is studied. Firstly， it combs the concept and connotation of routine transfer， and theoretically discusses the interaction among routine transfer， internal and external environments， knowledge ability and teamwork. Based on the principal component analysis (PCA) and random forest (RF) model， the important factors that affect routine transfer are explored. A quantitative analysis of the interaction and relationship of the factors is given to evaluate the difficulty of routine transfer. Based on the analysis of routine transfer in the air pollution control in Beijing-Tianjin-Hebei region from 2015 to 2019， it is found that routine transfer is affected by different environmental factors and is in the process of continuous evolution. Knowledge resources and economic environment are important and effective factors for the transfer of most routines， which are prone to transfer in other environments， while terminal governance increases the transfer difficulty of knowledge resources (general knowledge). Natural resources， natural environment and other factors are the main conflict factors in the process of routine transfer， which makes it difficult to replicate routines in other environments.

Key words: routine transfer; inter-project learning; air pollution control; factor analysis; combination of environmental factors