According to the characteristics of the soft soil subgrade reinforced by geosynthetic and piles, the deformation of geosynthetic was modeled as circular arc and the arching effect in embankments and the interaction of piles and soil are both considered in the calculation. The interaction mechanism of geosynthetic, pile and soil under the embankment load was analyzed. The method presented in this paper was validated by comparing with the testing results and three current design methods in the literature. The results show that the analytical solutions have agreement with the measured data and can be applied in engineering practice. Finally, four important parameter (the differential settlement, the diameter of pile, the width of pile cap, the height of equal settlement plane) were investigated.