Abstract: According to the working characteristics of the bidirectional reinforced composite foundation under embankment loads, the embankment and composite foundation in the equivalent reinforced range of a single pile are regarded as a typical analysis element. The large deflection circular ring thin plate is introduced to simulate the combined effect of “flexible raft” and “tensioned membrane” of the reinforced mattress. And the layered property of the foundation soil is considered based on the assumed model for the relative displacement between the pile and the soil. A mechanical model with consideration of deformation compatibility between the embankment, reinforcement and pile-soil reinforcement area is established based on the above operation, and the methods for calculating the load sharing ratio and settlement are proposed respectively. Field tests are used to verify the proposed method and the influence of the factors such as height of embankment, width of pile cap and tensile modulus of reinforcement on the position of neutral point, differential settlement and maximum tensile stress in the middle plane. The comparative results indicate the proposed method is feasible to be used in the practice.