In　current　researches,　although　the　calculation　method　of　the　foundation　pit　enclosure　structure　based　on　p-y　curve　has　considered　the　actual　situation　for　which　the　inside　soil　of　the　foundation　pit　may　enter　into　the　plastic　state,　it　has　not　considered　the　lateral　displacement　of　the　retaining　wall　when　the　internal　bracing　is　erected,　which　starts　working　after　the　retaining　wall　has　occurred　the　initial　displacement.　In　view　of　the　above-mentioned　shortcomings,　this　paper　presents　a　calculation　model　of　the　foundation　pit　enclosure　structure　based　on　p-y　curve,　considering　the　initial　displacement　of　the　retaining　wall　where　the　internal　bracings　erect　at　the　time　of　bracing.　The　finite　difference　equations　and　methods　for　lateral　displacement　calculation　of　enclosure　wall　are　established;　and　then　the　rationality　of　the　proposed　method　is　verified　by　case　studies.　Theoretical　analysis　and　case　studies　are　all　shown　that　the　calculation　method　of　the　foundation　pit　enclosure　structure　based　on　p-y　curve　is　reasonable.　©　2018,　Science　Press.　All　right　reserved.