Abstract: Abstract：Based on the geological-tectonic characteristics in Beijing plain，combined with the problems that have emerged in the study of active faults in recent years，the authors carried out the division of “small blocks” in Beijing plain, and recognized 7 small blocks, which are Machikou-Shahe small block, Xiaotangshan small block, Shunyi small block, Pinggu small block, Fengtai-Laiguangying small block, Daxing-Tongzhou small block and Fangshan small block. In accordance with active faults and the Quaternary sedimentary characteristics in the small block, the small block was further divided into several micro blocks. It is suggested that, in analyzing the activity, the viewpoint should be changed from active fault to active block. The authors revealed the activity of interactional microblocks and their sedimentation during the Quaternary period. This model plays an important role in city planning and construction and provides valuable reference for reducing geological hazards, thus ensuring the safety of urban geology.