In　this　study,　the　monopile　of　a　10　MW　offshore　wind　turbine　(OWT)　is　designed　for　a　specific　ocean　site,　and　a　new　soil-structure　interaction　(SSI)　framework　is　developed　for　the　aero-servo-hydro-elastic　code　FAST.　Taking　the　DTU　10　MW　OWT　as　the　prototype,　a　Bladed-style　controller　is　developed　to　regulate　the　rotor　speed　and　blade-pitch　angle,　and　its　performance　is　evaluated　by　comparisons　with　the　DTU　original　controller.　Subsequently,　an　SSI　analysis　model　is　established　for　FAST　using　the　nonlinear　Winkler　foundation　model,　and　this　module　is　verified　by　the　analysis　results　obtained　from　GL-Bladed　software.　In　addition,　the　monopile　of　this　10　MW　OWT　is　designed　for　layered　sand　adopting　the　metocean　data　from　the　North　Sea.　The　soft-stiff　design　philosophy　is　used　in　this　task,　and　the　1st-order　natural　frequency　of　the　system　is　0.22　Hz　lying　in　the　middle　of　1P　and　3P　frequency　bands　of　OWT.　Besides,　the　dynamic　response　and　fatigue　damage　of　this　10　MW　monopile　supported　OWT　are　investigated　using　the　fully　coupled　model.　The　results　show　that　SSI　effect　and　time-variant　blade-pitch　angle　significantly　influence　the　dynamic　response　of　OWT　and　fatigue　life　of　the　monopile.