Abstract: Based on a thorough study of the deformation mechanism for gravel pile composite ground under flexible foundation, a new method for gravel pile composite ground settlement analysis is set up by using the soil displacement in a unit cell mode. Firstly, the existing vertical displacement model is improved for considering the relative slip between pile and soil in gravel pile composite ground under flexible foundation .Secondly, because the lateral displacement for gravel pile in composite ground cannot be ignored, the analysis method is combined with the influence of the radial displacement. The method for analyzing the friction on pilesoil interface is established. Finally, through the analysis of the unit cell model the analysis method for the displacement in the treated area is obtained. The analysis method can not only reflect the interaction between pile and its surrounding soils as well as the characteristics of slip between piles and soil, but also consider the influence of the lateral deformation of the gravel pile in composite ground settlement analysis. The engineering examples show that the method proposed in this paper is of feasibility and rationality.