Abstract:A new technology,impact compaction technology in improving collapsible loess roadbed,is studied. The effects of the improvement are analyzed qualitatively and quantitatively,both in macroscale and microscale, through routine soil tests and microstructure testing methods such as scanning electron microscope and mercury intrusion porosimetry. The improvement mechanism of the technology is discussed and reasonable parameters for roadbed construction process are put forward as to provide theoretical basis as well as practical experience for the promotion of this new technology in the loess regions.