Metamaterial　Perfect　Absorber　(MPA)　is　currently　a　research　hotspot　because　of　its　numerous　advantages　such　as　high　absorption　efficiency,　ultra-thin　thickness,　simple　structure　and　so　on.　Since　Landy　et　al.　first　proposed　an　MPA　with　perfect　absorption　characteristics,　different　types　of　MPAs　have　been　proposed,　and　the　absorption　wavelengths　over　microwave,　terahertz,　infrared,　and　visible　bands　have　been　identified.　However,　once　the　structural　parameters　of　MPA　are　fixed,　the　absorption　bandwidth　of　MPA　almost　cannot　be　dynamically　adjusted,　which　will　limit　its　applications　in　some　particular　fields.　This　paper　proposes　a　bandwidth-tunable　MPA　which　is　composed　of　vanadium　dioxide　(VO2)　and　Au.　The　research　group　simulated　and　analyzed　the　MPA　based　on　Finite　Difference　Time　Domain　(FDTD)　method.　In　the　simulation,　a　periodic　boundary　condition　was　added　in　x-　and　y-directions,　and　a　perfect　match　layer　was　added　in　the　z-direction　as　the　boundary　condition.　The　polarization　of　the　incident　light　was　set　to　be　TM　polarization　(Along　the　x　axis).　Incident　light　was　perpendicular　to　the　surface　of　the　structure,　which　indicated　the　incident　angle　θ　is　0.　The　simulation　results　show　that　the　tuning　range　of　absorption　bandwidth　can　achieve　0.378　μm　by　controlling　the　temperature　of　VO2,　and　the　absorption　wavelength　of　MPA　covered　visible　and　near-infrared　light.　To　explore　the　physical　explanation　for　the　high　absorption　efficiency　in　different　wavelengths,　we　analyzed　electromagnetic　field　distribution　in　MPA　in　different　wavelengths,　and　revealed　that　although　the　high　absorption　efficiency　is　caused　by　the　incident-light-stimulated　surface　plasmons　in　MPA,　the　working　mechanism　in　visible　and　near　infrared　wavelength　is　quite　different.　In　visible　light　range,　no　matter　vanadium　dioxide　is　in　metallic　state　or　dielectric　state,　the　high　absorption　efficiency　is　caused　by　Propagating　Surface　Plasmon　(PSP).　On　the　other　hand,　for　near-infrared　light,　if　vanadium　dioxide　is　in　dielectric　state,　the　high　absorption　efficiency　is　due　to　the　Localized　Surface　Plasmon　(LSP);　or　if　vanadium　dioxide　is　in　metallic　state,　the　high　absorption　efficiency　is　due　to　Fabry-Perot　(FP)　cavity　resonance.　Our　results　show　that　the　MPA　has　the　potential　to　be　used　in　applications　such　as　optical　integrated　devices　and　thermal　emitters.　©　2022,　Science　Press.　All　right　reserved.