The　suction　bucket　foundation　offers　cost-effective　and　simple　construction　method　for　offshore　wind　turbines　(OWTs).　However,　marine　environment　involves　complex　loading　schemes,　where　suction　bucket-supported　OWTs　would　be　subjected　to　wind,　waves,　currents,　and　earthquake　loading,　and　may　be　subject　to　scour　caused　by　prolonged　wave　and　current　actions.　Currently,　there　is　a　paucity　of　research　on　how　scour　influences　the　dynamic　response　of　suction　bucket-supported　OWTs.　This　study　systematically　investigates　the　influence　of　scour　on　the　dynamic　responses　of　suction　bucket-supported　OWTs　under　seismic,　wind,　and　wave　loads　through　comprehensive　three-dimensional　numerical　analysis.　Research　findings　demonstrate　that　scouring　can　decrease　the　natural　frequency　of　suction　bucket-supported　OWTs　by　up　to　approximately　1%　and　the　lateral　ultimate　bearing　capacity　by　up　to　approximately　10%.　Scouring　amplifies　the　dynamic　response　of　OWTs　under　windwave　loads,　with　the　wind　speed　exerting　a　more　pronounced　influence　compared　to　the　wave　height.　Scouring　weakens　the　bucket-soil　kinematic　interaction　and　increases　energy　dissipation,　which　reduces　the　seismic　response　of　the　wind　turbine　structure.　Seismic　loads　predominantly　influence　tower　vibrations　compared　to　wind-wave　loads.　In　scenarios　where　earthquakes　coincide　with　wind　waves,　wind-wave　loads　can　mitigate　the　acceleration　induced　by　seismic　forces　to　some　extent.　There　exists　a　nonlinear　coupling　relationship　between　wind　and　wave　loads,　as　well　as　earthquake　loads,　making　it　advisable　to　employ　a　fully　coupled　method　for　OWTs　response　calculations.