Laser cladding Ni-based alloy with tungsten carbide are yielded on the surface of 20Cr-NiSiW substrate ,and the stress status of cladding layer is analyzed. The stress distribution of cladding layer can ameliorate with before cladding preheating and after cladding thermal retardation. The microstructure of cladding layer and hardness distribution are discussed. Cracks are decreased between the surface of cladding layer and the substrate building transition layer of good toughness. The cladding technology and non-cracks of cladding layer are improved.