This paper introduces the characteristics of collapsible loess and its processing method, and emphatically introduces the concept of the compaction pile, development history and its applicable conditions. Mainly discussed lateral eompac tion pile contribution to ruination effects of loess collapsibility and chemical reaction of cement with water, soil contribution to the decisive role of reinforced composite foundation bearing capacity. By engineering example describes the design process and methods compacted soil-cement pile composite foundation construction process and ramming expanded dense cement soil pile and material requirements, quality control. This is the experience for reference of rammed cement-soil compaction pile further promoted in the same building in the same area.