Theemergingperfect-absorbermetamaterials(PAMs)provideanalternativematerialapproachforthenextgenerationofelectromagneticdetectionatanyfrequencybandofinterest.Onetypeofdualcross-shapedPAMsisdevelopedtoobtainmultiplex-bandspectrumabsorptionatmid-infraredregion.Threedistinctabsorptionpeaksareattributedtothepolarizationsensitivityexcitationoftheplasmonicresonance.Thechargedensitydistributions,whichareexcitedbyresonantelectromagneticwavespassingthroughthePAMsmedium,provideinsightsintotheobservedabsorptionbehavior.WefindthattheretrievedopticalpropertiesofthePAMsincludingpermittivityandpermeabilityarestillconsistentwiththesumoftheDrudeandLorentztypemodelsatwavelengthsrangingfrom2.0to10.0mm.Suchmultiplex-bandabsorptionpropertiesenabletheproposedPAMsapowerfultoolforthedirectdetectionofmultiplemolecularvibrationalstructures,andformultiplespectrainfrareddetection.