The work aims to obtain the cladding layer with excellent comprehensive properties on Cr12MoV by introducing the surface roughness of substrate as a process parameter of laser cladding with wire, so as to study the effects of laser power, wire feeding speed, scanning speed and surface roughness on clad geometry. SKD11 steel wire was deposited on Cr12MoV plate by Nd:YAG pulsed laser to repair the die surface damage. The microstructure and chemical composition of cladded samples were characterized by optical microscope, SEM and EDS and the microhardness profiles was determined via the microhardness tester. From the experiment results, the surface roughness had significant impact on morphology of cladding layer due to the light trapping effect. With the increases of roughness, the laser absorption ratio was improved and both the clad depth and the dilution increased, but the height decreased. The essence of influence mechanism was the effective body energy Ev and the specific filling rate ω. When Ev was 80~100 J/mm3 and ω was 1~3, a relatively stable cladding process could be obtained. The cladding layer consisted of a mixture of cellular grain, columnar grain and equiaxed grain where the grains were fine and hard vanadium carbide particles existed. Thus, the surface hardness increased to 900 HV, 3 times over that of the base metal. Ev and ω can be used as key process factors. In the specific category of Ev and ω, a flat cladding layer with low dilution, less fusion defects, high hardness and no apparently softened zone can be obtained and laser cladding with wire meets the requirement of die repair.