Abstract: Adopting the FEM,calculation and analysis have been undergone for ground vertical deformation,shear force within foundation slab and distribution of bending moment on the basis of four modes that are raft on the natural foundation of existing building,piling surrounding raft basis,soft soil grouting and lateral reinforcement grouting substitution separately.Under the calculated circumstance,the way of lateral reinforcement grouting substitution is able to abate both the structure's settlement,accounting for only half of the natural one,and contemporarily additional stress within the foundation slab,whose most shear force and bending moment are decreased by over 54% and 47% respectively compared with reinforced piling around the structure periphery.Furthermore,the strengthened foundation's mechanical property is closer to that of the natural one under which most structures are designed,favoring the base work and avoiding excessive stress adjustment inside the foundation.In addition,the construction of strengthening the foundation by the technique is carried out outdoors for the purpose of overall stabilization without influencing either the normal life of citizens on the ground floor or factory' work.