With　larger　rotors　and　taller　towers　developed　to　capture　more　wind　energy,　the　wind　turbine　structures　are　becoming　more　flexible　with　aspect　ratio　increasing.　However,　there　remains　a　strong　gap　of　dynamic　analysis　of　fully　coupled　high-aspect-ratio　wind　turbine　tower　system.　This　study　employed　the　IEA　15　WM　wind　turbine　as　a　reference　prototype,　and　designed　a　scaled　model　based　on　the　geometric,　kinematic,　and　dynamic　similarity　principles.　Then,　the　systematic　investigations　of　dynamic　behavior　of　coupled　wind　turbine　tower　system　were　performed　tested　combined　wind　tunnel　tests　with　computational　fluid　dynamics　(CFD)　modelling.　The　dynamic　behavior　was　analyzed　in　terms　of　acceleration　and　displacement　responses,　motion　trajectories,　and　dynamic　characteristics　in　both　crosswind　and　downwind　directions.　In　CFD　modelling,　the　aerodynamic　characteristics　were　revealed　in　terms　of　the　average　pressure　coefficient,　fluctuating　pressure　coefficient,　and　lift　and　drag　forces.　Parameter　discussions　were　performed　including　the　blade　rotation,　turbulence　intensity　and　wind　speed.　The　results　indicate　that　turbine　vibrations　are　highly　sensitive　to　variations　in　wind　speed　and　turbulence.　As　wind　speed　and　turbulence　increase,　the　range　of　vibration　data　expands,　with　peak　responses　amplified　by　249.70　%　and　59.63　%,　respectively,　and　lift　forces　increasing　by　over　40　%.　Furthermore,　blade　rotation　increases　the　average　pressure　coefficient　by　up　to　42.09　%.　Compared　to　the　previous　studies　of　low-aspect-ratio　wind　turbine　tower　case,　high-aspect-ratio　wind　turbine　tower　exhibit　significantly　more　intense　vibrations　in　the　same　operating　cases,　with　an　increase　in　the　root　mean　square　(RMS)　of　acceleration　up　to　52.50　%.　Additionally,　the　slender　tower　structures　are　more　susceptible　to　higher-order　frequency　excitations　induced　by　fluid　solid　interactions　during　operation.