The　research　is　intended　to　prepare　CoCrFeNiMo　high-entropy　alloy　containing　refractory　metal　Mo　on　the　low　carbon　steel,　and　do　some　researches　about　the　microstructure　and　mechanical　properties　of　this　cladding　layer,　and　then　provide　theoretical　reference　and　the　experimental　example　for　the　subsequent　research　of　high　melting　point　high-entropy　alloy　in　surface　engineering.　Co,　Cr,　Fe,　Ni,　Mo　metal　powders　were　mixed　evenly　according　to　the　equal　molar　ratio.　And　then　the　CoCrFeNiMo　high-entropy　alloy　cladding　layer　was　manufactured　on　Q235　steel　by　plasma　cladding.　The　alloy　components,　crystal　structure,　microstructure　and　microhardness　of　this　cladding　layer　were　investigated　by　XRF,　XRD,　OM,　SEM　and　microhardness　tester.　The　results　showed　that　due　to　the　element　burning　phenomenon　in　the　process　of　plasma　cladding,　the　actual　composition　of　the　cladding　layer　was　Co1.17Cr0.92Ni1.06Fe0.92Mo0.92.　The　cladding　layer　formed　a　good　metallurgical　bond　with　the　substrate.　The　cladding　layer　was　mainly　composed　of　FCC　phase　with　a　small　amount　of　σ　phase.　The　microstructure　was　dendrite　structure.　Furthermore,　the　dendrite　was　FCC　phase　with　a　variety　of　elements,　and　the　interdendrite　was　eutectic　structure　composed　of　FCC　phase　and　σ　phase　rich　in　Mo　and　Cr.　In　addition,　the　phase　formation　law　of　high-entropy　alloy　was　very　complex　and　its　phase　structure　could　not　be　predicted　only　by　thermodynamic　parameters,　but　still　needed　to　be　verified　by　experimental　results.　Due　to　the　solid　solution　strengthening　of　Mo　element　and　the　precipitation　strengthening　of　σ　phase,　the　hardness　of　the　cladding　layer　was　obviously　improved,　and　the　hardness　of　the　surface　was　about　485HV.　Therefore,　the　CoCrFeNiMo　high-entropy　alloy　cladding　layer　is　successfully　prepared　on　Q235　steel　by　plasma　cladding.　The　hardness　of　CoCrFeNi　high-entropy　alloy　is　improved　by　adding　Mo.　©　2022,　Chongqing　Wujiu　Periodicals　Press.　All　rights　reserved.