Laser　cladded　NiCrBSi　alloy　coating　was　fabricated　on　the　surface　of　a　42CrMo　roll　using　a　6　kW　fiber　laser.　The　effects　of　the　laser　power,　scanning　speed　and　feeding　rate　on　the　cladding　layer　form,　size,　dilution　rate,　microstructure,　and　hardness　of　coating　were　studied　by　using　optical　microscopy　(OM),　scanning　electron　microscopy　(SEM)　and　a　microhardness　tester.　The　results　show　that　the　microstructure,　size,　dilution　rate　and　hardness　of　the　cladding　layer　had　changed　with　an　increase　in　laser　power,　powder　feeding　rate　and　scanning　speed.　The　appropriate　parameters　of　the　laser　cladding　experiment　are　as　follows:　the　laser　power　is　2000　W,　powder　feed　rate　20　g　x　min(-1),　the　scanning　speed　4　mm　x　s(-1).　The　cladding　layer　and　the　substrate　exhibit　good　metallurgical　bonding　under　the　above　processing　parameters.　The　microstructure　of　the　cladding　layer　is　fine,　the　dilution　rate　is　9.8　wt.-%,　and　the　microhardness　of　the　cladding　layer　is　710.7　HV.