In　order　to　more　reliably　calculate　the　displacements　and　internal　forces　of　anti-slide　piles,　the　pile-soil　composite　stiffness　under　combined　action　and　subgrade　resistance　tri-parameter　method　is　presented　to　calculate　anti-slide　piles.　Based　on　this　method,　numerical　solution　of　link　finite　element　is　established.　According　to　the　measurements　of　displacements　and　bending　moments　of　an　engineering　pile　pushing　test,　the　pile-soil　composite　stiffness　under　combined　action　and　subgrade　resistance　tri-parameter　are　back　analyzed.　Then　the　calculation　results　obtained　by　finite　element　analysis　are　compared　with　the　measurements　of　pile　displacements　and　bending　moments　under　different　load　grades.　The　results　show　that　the　horizontal　resistance　parameters　of　rocks　and　soils　are　nonlinear.　With　the　increase　of　pile　displacements　caused　by　larger　loads,　the　horizontal　subgrade　resistance　parameters　obviously　decrease　and　the　pile-soil　composite　stiffness　under　combined　action　diminishes　to　a　certain　extent.　©,　2014,　Academia　Sinica.　All　right　reserved.