Foundation collapsibility is one of the factors that affect the foundation stability in loess area, and is also the major form that causes the building damages. Analysis and introduction were made on the application of composite foundation treatment methods and the technical effects in Xi’an City. The paper demonstrated the application of composite foundation treatment methods in collapsible loess ground, which can eliminate part or all collapsibility in collapsible loess to improve the foundation bearing capacity and decrease the ground deformation.