Abstract: Combined with an engineering case where lime-soil compaction pile is used to treat subsidence loess, the changes in mechanical property of loess around the pile are analyzed, including the strength property and subsidence of the composite foundation after the treatment. The results show that the application of lime-soil pile in treatment of subsidence loess can improve the engineering properties of the soil between piles effectively, also eliminate subsidence of loess and enhance the bearing capacity of composite foundation.