This paper regarded the force and deformation characteristics of geocell reinforcement，as a small deflection of an elastic circular thin plate. Taking into account the deformation compatibility between the geocell and pile-soil reinforced area，horizontal-vertical coupling deformation of the geocell-reinforced mattress，as well as the horizontal friction effect of the top and bottom plate-soil interface，the governing differential equations of the geocell flexural deformation were established under symmetric load. The analytic expressions of vertical and horizontal displacement were constructed by the Bessel complex-variable functions，from which the calculation formulas were deduced for pile-soil stress ratio below the net, settlement and differential pile-soil settlement. To verify this method, an existing case was employed. Finally，the effects of various factors were discussed, which show that it is beneficial to modify the pile-soil stress ratio below the net and to reduce the embankment settlement by changing the composite elastic modulus, the pile-soil stiffness ratio and horizontal frictional coefficient ratio to some extent.