Abstract: During the recent years,the composite foundation's deformation design is a difficult problem.A new design concept for composite foundation,whose kernel is to regulate the deformation of the base-bottom and the composite and to make them approximately equal,is put forward.The method to regulate the deformation of the base-bottom and the composite is to execute through regulating the piles' and the cushion's parameters,regulating the foundation's rigidity.As a complement of this new design concept,the developing procedure of DCDS,which is the briefcase of "composite foundation Deformation Control Design System",is described briefly.In order to develop and complete this new design concept,several important tasks are concluded and emphasized.