By　adding　B4C　and　vanadium　to　Ni45-Cr3C2　powder　in　a　moderate　proportion,　it　is　found　that　B4C　will　decompose　into　elements　B　and　C　during　laser　cladding,　and　the　lattice　constants　of　V　and　Cr　elements　are　similar,　which　can　form　(Cr,V)B-2　phase　with　high　hardness.　According　to　the　first　principles　calculation　of　the　hardness　of　(CR1-XVx)B,　it　can　be　seen　that　it　shows　a　trend　of　increasing　first　and　then　decreasing.　With　the　addition　of　B4C　and　vanadium,　the　mechanical　properties　of　the　composite　coating　increase.　When　the　coating　composition　is　Ni45-30Cr(3)C(2)-9B(4)C-15FeV50,　the　average　microhardness,　fracture　toughness　and　wear　resistance　of　the　composite　coating　increase　by　22.1%,　121.6%　and　54.2%,　respectively.