In　this　study,　Ni-based　composite　coatings　with　(Cr,　V)　B-2　ceramic　particles　were　reinforced　using　varying　Y2O3　concentrations　for　crack-free　layers　on　40CrNiMo　steel　surfaces.　We　investigated　the　phase　composition,　microstructure,　microhardness,　wear　resistance,　fracture　toughness,　and　the　reinforcement　mechanism　of　Y2O3　within　the　composite　cladding.　Using　SEM　and　TEM,　we　revealed　the　pivotal　role　of　rare　earth　oxide　Y2O3　in　refining　grains　and　forming　uniform,　densely-packed　microstructures　in　the　coatings.　The　resulting　cladding　layer　mainly　consisted　of　fine,　strip-like　precipitates　of　the　gamma-Ni　phase,　along　with　ceramic　reinforcement　particles　like　CrB2,　VC,　and　VB2.　Unmelted　Y2O3　and　preferentially　nucleated　VC　served　as　nucleation　sites　for　(Cr,　V)　B-2　particles,　contributing　to　the　overall　structural　integrity.　Our　findings　showed　that　an　optimal　quantity　of　Y2O3　moderately　increased　the　hardness　to　a　maximum　of　1049.4　HV0.2.　Additionally,　with　increased　Y2O3　content,　the　cladding　layer　exhibited　enhanced　wear　resistance,　improved　fracture　toughness,　and　reduced　susceptibility　to　cracking　due　to　complete　plastic　deformation.　However,　excessive　Y2O3　addition　led　to　a　decline　in　wear　resistance,　emphasizing　the　importance　of　carefully　controlling　Y2O3　content　for　optimal　coating　performance.　These　results　highlight　the　potential　for　Y2O3　to　enhance　Ni-based　(Cr,　V)　B-2　ceramic　particle　composite　coatings,　positioning　them　as　promising　candidates　for　advanced　surface　enhancement　applications　in　materials　science　and　engineering.