In　this　paper,　an　experimental　study　on　the　mechanism　and　mechanical　properties　of　the　shear　connectors　in　such　deconstructable　steel-concrete　composite　beams　is　conducted　in　order　to　promote　the　development　of　full　life-cycle　deconstructable　steel　structures　and　steel-concrete　composite　structures,　and　to　improve　the　relevant　mechanical　performance　evaluation　methods　and　structural　design　methods.　Incorporating　variations　in　connector　(bolt)　diameter　(M20,　M24)　and　material　strength　(C50,　C60　concrete),　this　paper　investigates　the　failure　mechanism,　load-slip　response,　slip　and　peak　load,　and　deconstructability　using　conventional　push-out　tests.　By　comparing　the　test　results　with　those　determined　by　shear　capacity　of　composite　beams　with　headed　studs　and　fasteners　with　bolt　stated　in　national　standards,　the　friction　type　shear　capacity　and　bearing　type　shear　capacity　calculation　techniques　of　this　novel　shear　connector　are　proposed.　On　the　basis　of　the　mechanism　analysis,　a　mechanical　constitutive　model　of　the　shear　connector　of　deconstructible　composite　beams　is　given,　with　each　parameter　established.　The　findings　demonstrate　that　the　proposed　characteristic　capacity　and　shear-slip　constitutive　model　can　accurately　represent　the　mechanical　characteristics,　hence　providing　the　theoretical　and　technological　foundations　for　its　implementation　in　deconstructable　steel-concrete　composite　beams.　©　2022,　Progress　in　Steel　Buiding　Structures　All　right　reserved.