Owing　to　the　complexity　of　the　sheet　pile　wall　with　a　relieving　platform,　there　are　a　large　number　of　factors　that　affect　the　mechanical　and　deformation　characteristics　of　the　wall　structure.　Moreover,　studying　the　influencing　factors　on　the　deformation　of　the　retaining　wall　is　beneficial　in　the　selection　of　design　parameters　and　deformation　control.　28　groups　of　test　models　of　the　retaining　wall　structure　are　designed　to　analyze　the　effect　on　the　deformation　of　rib　pillars　and　determine　the　reasonable　width　and　buried　depth　of　the　unloading　board　in　this　paper.　The　tests　are　conducted　with　and　without　the　unloading　board,　and　different　widths　and　buried　depths　of　the　unloading　board　are　also　considered.　The　findings　show　that,　without　the　external　load,　the　reasonable　board　width　and　buried　depth　are　0.70　times　and　0.53　times　the　wall　height.　With　the　external　load,　the　reasonable　board　width　is　0.35　times　the　wall　height,　and　the　large　board　width　cannot　effectively　reduce　the　deformation　of　rib　pillars,　and　the　reasonable　board　width　is　0.60　times　the　wall　height.　When　both　the　external　load　and　board　width　are　relatively　small,　the　reasonable　buried　depth　is　0.53　times　the　wall　height.　However,　when　the　external　load　is　large,　the　reasonable　buried　depth　is　0.70　times　the　wall　height.　The　results　also　show　that　the　setting　of　the　unloading　board　effectively　suppresses　the　deformation　of　rib　pillars　and　controls　the　maximum　deformation　within　an　allowable　range　of　the　specification.