Based on the relationships of the differential settlement of piles and soil, soil arch effect and load distribution, an assumption that the volume of pile into the embankment is equal to the compression amount of the soil arch volume was firstly put forward. Combined with the mechanical analysis of pile-supported embankment and the deformation equilibrium of piles and soil, the formula between the pile-soil stress ratio and the soil arch height with differential settlement was derived. Finally, comparative model test and numerical analysis were performed to check the validity of this method. The proposed method was also used for a parametric study in order to investigate the effects of various parameters such as replacement ratio of pile and soli area, embankment height, and friction angle of the soil on the behavior of the pile-soil stress ratio and soil arch height. The result turned to be in good agreement with the measured values, which verifies the rationality of the proposed method.