The proposed project in this paper is mountain slope foundation engineering, the collapsible subsoil should be eliminated and the characteristic value of bearing capacity fak≥130kPa is required. In addition, slope stability and permanent reinforcement should be taken into account. The project was deeply analyzed and concept design method was used to preview the design. As complex process, difficult practice and some hidden troubles for permanent use were found, the project was re-analyzed, and it was suggested to take the socket pile as the foundation in stead of the original foundation treatment measures.