Abstract: The laser cladding of high speed steel (HSS) powders on nodular cast iron rolls was carried out using Nd:YAG pulse laser. The optimized laser processing parameters obtained through single-path cladding experiments are as follows: the electric current is 240 A, the scanning velocity 3 mm/s, the defocus amount 13 mm, the thickness of cladding layer 0.5 mm, the frequency 15 Hz and the impulse width 3.0 ms. Based on the parameters mentioned above, multi-path overlapping cladding experiments were conducted. The results show that the cladding is bonded metallurgically to the substrate, with some cracks in the layer observed, and the main strengthening phases are WC1-x and V4C3. The average microhardness of the cladding was 600 HV with the maximum up to 682 HV, which was about 2.3 times as high as that of the substrate. Adding 50% Ni60 to HSS powders reduced the crack numbers effectively, while the microhardness decreased to 637 HV, about 2.1 times as high as that of the substrate.