As　a　flexible　component　in　high-pressure　vessels　and　pipeline　systems,　bellows　experience　significant　fluid-structure　interaction　effects　under　high-speed　internal　fluids　and　external　vibrations.　Nevertheless,　their　dynamic　response　mechanisms　coupled　with　fluid-structure　interaction　mentioned　below　have　not　yet　been　clarified　so　far.　In　this　work,　a　novel　pressure-balanced　metal　bellow　(PBMB)　for　low-stiffness　and　high-pressure　resistance　is　firstly　proposed.　Several　fluid-structure　interaction　models　were　considered　to　study　the　dynamic　response　characteristics　of　the　PBMB.　An　experimental　platform　associated　with　fluid-structure　interaction　was　established　to　validate　the　effectiveness　of　its　vibration　attenuation　performance.　The　results　indicate　that　the　PBMB　has　an　obvious　vibration　attenuation　effect　in　the　range　of　5-90　Hz,　and　super-harmonic　and　sub-harmonic　resonance　phenomena　occur　in　the　range　of　90-200　Hz.　Under　constant　fluid　conditions,　fluid　density,　viscosity,　flow　velocity,　and　pressure　are　positively　correlated　with　the　response　amplitude　of　the　PBMB.　The　response　of　the　PBMB　oscillates　at　the　fluid　entry　point　due　to　both　pulsating　flow　velocity　and　pulsating　pressure.　After　several　cycles,　the　response　caused　by　pulsating　flow　velocity　gradually　decays　and　stabilizes.　Thus,　the　impact　of　pulsating　frequency　on　the　stability　of　the　response　of　bellows　is　insignificant　during　the　initial　cycles.　©　2025　World　Scientific　Publishing　Company.