Research conclusions :(1) Moving the first support position up was conducive not only to control the pile deformation， but also to control strength of the pile body. (2) It was effective to reduce deformation of the retaining structure by in- creasing the support stiffness when the support stiffness was smaller. (3) It was not economical to control the deformation of the retaining structure by increasing the support stiffness when the support stiffness was larger. When it was the same reinforcement thickness in passive area，it could better control the deformation of the retaining structure and im- prove the stress of the retaining structure selecting the reinforcement below the bottom excavation surface than selecting the reinforcement above the bottom excavation surface. (4) As the excavation depth increased，the maximum displacement of the pile body gradually moved downward， And the producing maximum displacement position would change by the difference of the support stiffness and the support prestressing.