Abstract: In the design of composite foundation, in addition to meeting the foundation bearing capacity also meeting the ground deformation design requirements. At present, the deformation calculation of composite foundation widely adopted semitheoretical, semi empirical method from ground handling practices, but a lot of settlement monitoring data show the real sedimentation of CFG pile composite foundation far less than calculated value which calculate according to standardized methods. This article aims at the defect of settlement calculation methods which about CFG pile composite foundation and reference researches in natural ground and composite foundation. This article proposes a correction formula and some personal opinions to get the goal which is safe and reliable economic and practical in the same time provide a theoretical basis for settlement calculation of CFG pile composite foundation.