This study aims to explore the bearing characteristics of rigid pile-net composite foundation with multi-layer reinforced cushion. Firstly, the reinforced cushion layer with multi-layer geogrids is regarded as a large deflection plate for simplification. The interaction characteristics between multi-layer geogrids and gravel cushions were analyzed based on laminating theory. The stiffness matrix of reinforced cushion was then derived. Considering the actual three-dimensional stress and displacement boundary of the rigid pile-net composite foundation, the stress function and the deflection differential control equations were deduced through the static equilibrium. Subsequently, Galerkin method was used to solve the equations. Based on the deformation of the reinforced cushion layer, the pile-soil stress ratio of rigid pile-net composite foundation was calculated through Winkler foundation beam method and the tension force of geogrids was derived via large deflection plate theory. Finally, the calculation method was validated by practical engineering. The factors that affect pile-soil stress ratio and tension force, such as total number of geogrids, geogrids spacing and location of the geogrids, were systematically analyzed. It is shown that the analytical solutions agree well with the measured data. With increase of the total number of geogrid layers, the pile-soil stress ratio increases and the geogrid tensile force decreases. The most efficient number of geogrid layers is 2 or 3. With the increase of vertical spacing between geogrids and the spacing from the bottom geogrid to pile cap, pile-soil stress ratio decreases and tension force increases. More importantly, these findings may provide guidance on optimal design of geogrid in engineering practice.