Abstract: Based on the conceptualization of pile shaft resistance, the method of Mindlin's solution to calculate the settlement of pile group foundation is studied. According to the thickness of the compressive layer, the stiffness contribution of the superstructure, the diversity of pile type in the variable stiffness leveling design and the settlement calculation of the composite pile foundation, a simple method for calculating the homogenized additional stress of the foundation pile is given in combination with the generalized mode of the specific lateral resistance distribution, different length-diameter ratios, and different pile spacings. The steps and rules for calculating the settlement of pile group foundation by the superposition layer summation method for the additional stress of pile homogenization are put forward. The settlement of pile groups is calculated by the proposed method for homogenized additional stress. Through the verification of engineering examples, compared with that of the Boussinesqs method for solid deep foundation and the equivalent action method, the calculated settlement is closer to the measured one.