The main pile with inlaid sheet structure is a type of sheet-pile wall with complicated force conditions.When the deformation of inlaid sheet increases，it will produce soil arching effect on the structure’s back side.Based on the introduction of soil arching theory，we build a plane strain model by ABAQUS software to study the impact of structure size and soil properties on soil arching effect.The results indicate that the structure size has a greater contribution to the effect.To a certain extent，the effect of soil properties is relatively small.In the design of main pile with inlaid sheet structure，in order to give full play to the soil arching effect and save project cost，main pile interval could be increased appropriately，and inlaid sheet thickness should be reduced within a certain scope.