In the light of the problem existing in the design and construction of collapsible loess foundation that the foundation subsides obviously and cause s damages of the buildings above it, and probes into the working mechanism and a pplication scope of replacement cushion method and compaction pile method.

It introduces some treatment measures of wet and sunken loess foundation,analyzes the foundation treatment principle according the characteristics of the wet and sunken loess,and represents the foundation treatment method that is soil cushion treatment first and the densely covered lime-soil pile treatment second,which show this treatment method having good effectiveness.