The　pile　foundation　used　in　offshore　wind　turbine　system　is　located　in　a　complex　marine　environment　and　is　subjected　to　various　long-term　cyclic　loads　such　as　wind,　wave　and　current.　However,　the　attenuation　effect　of　long-term　cyclic　load　on　seabed　soil　has　not　been　considered　by　most　of　the　existingp-y　curve　calculation　models.　In　order　to　solve　this　problem,　the　finite　element　numerical　model　of　pile-soil　interaction　of　large　diameter　single　pile　foundation　of　offshore　wind　turbine　is　established　in　this　paper.　Based　on　the　Stokes　second-order　wave　theory,　the　time　history　curve　of　wave　and　current　loads　on　piles　with　different　diameters　are　derived　and　calculated　by　programming.　Then　the　soil　stiffness　attenuati　on　model　subjected　to　marine　cyclic　loading　is　embedded　into　the　finite　element　model　by　subroutine.　Considering　the　influence　of　the　number　of　ocean　load　cycles　on　the　ultimate　soil　resistance　of　the　soil　around　the　pile　and　the　initial　foundation　reaction　modulus,　the　calculation　results　of　different　pile　diameters　and　soil　depths　are　analyzed　and　regressed.　Finally,　the　p-y　curve　calculation　model　of　large　diameter　single　pile　foundation　of　offshore　wind　turbine　under　long-term　ocean　cyclic　load　is　obtained.