As　a　blockchain　consensus　mechanism　based　on　Byzantine　fault　tolerance,　PBFT　has　a　very　important　role　to　play　in　the　field　of　consortium　blockchains.　However,　in　the　context　of　the　Internet　of　Things,　the　poor　scalability　of　PBFT　limits　the　application　of　blockchain　in　the　face　of　a　large　number　of　replicas　and　an　unstable　network　structure.　To　achieve　the　consistency　of　replicas　in　the　Internet　of　Things,　this　article　proposes　a　monitory　Byzantine　fault　tolerant　mechanism,　a　type　of　monitor　node　is　added　to　the　network　model.　The　monitor　nodes　measure　the　behavior　and　judge　the　status　of　the　replicas　in　the　blockchain.　The　monitor　node　can　not　only　guide　the　new　node　join　the　blockchain,　but　also　use　the　trust　measurement　table　to　sense　the　status　of　the　nodes,　and　eliminate　malicious　nodes　or　crashed　nodes.　To　verify　the　effectiveness　of　the　proposed　replica　elimination　method,　a　verification　simulation　experiment　is　performed.　And　the　experiments　show　that　the　proposed　mechanism　has　good　stability,　good　effectiveness　and　accuracy　for　Byzantine　node　elimination,　and　improves　the　security　of　the　consensus　mechanism.　©　2021　IEEE.