In order to establish a theoretical method that can fully consider the coordinated deformation characteristics between the components of pile-supported embankments. A double equal settlement plane model is established which introduced a equal settlement plane in the substratum and considered the deformation mechanism of the pile-supported embankments with the flexible pile. Firstly, the model introduce an equal settlement plane at a certain depth below the pile-toe base on the deformation characteristics of the pile-supported embankment and the equal settlement plane in the embankment. Secondly, considering the deficiencies of the existing soil column model, an new soil column model that can consider the influence of the relative displacement on the side pressure coefficient between the inner and outer soil columns is proposed. The embankment, pile and soil between the two equal settlement plane affect the stress at equal settlement plane by the coordinated deformation of each other, thus affecting the overall settlement of the embankment and the pile-soil stress ratio. Finally, the calculation results of the proposed method and the composite modulus method are compared with the measured values. The results show that the calculation errors of settlement are 9.67% and 19.4%, respectively. The relative error of pile-soil stress ratio calculated by the proposed model is 9.91%, which verifies the rationality of the proposed model.