Based on the data of train numbers of intercity railway transport of passengers, the content of urban interaction can be depicted effectively, and the systematic structure and status of the spatial pattern can be recognized, by constructing important screening tools for indicators of spatial linkage of urban system. In order to deeply reflect the possibility of urban interaction in the Beijing-Tianjin-Hebei region, this study's estimation result indicates: There exist significant regional differences in urban absorption capacity of the passenger railway transport, manifesting obvious first-place distribution characteristics in terms of scale while rendering "N-type" distribution characteristics with Beijing and Tianjin and Shijiazhuang as major nodes in spatial terms. The geographical location (exogenesis) and absorption capacity (endogenesis) jointly shape the urban interaction pattern of this region. The empirical result evinces: The spatial variation of the range of central cities' hinterland takes on a distinct tendency. The intensity of attachment of all cities to Beijing is independent of their spatial location and geographical position while rendering a regularity of graded distribution. Policy inspires: all cities need to comply with the possible anchoring force of "strong-strong cooperation" to advance Beijing-Tianjin-Hebei synergic interactive development, namely hinterland cities with stronger urban absorption capacity shall bear closer interactive relationship to the central city. The operation of high-speed railway changes urban growth path and urban interaction pattern and can significantly drive regional investment. But there is uncertainty in the long run. Hinterland cities should prudently treat the short-term effects of economy and population size dilation brought along with high-speed railway.