The YLS-3000 fiber laser is used to laser cladding of the Co-based superalloy. The macro-morphology, microstructure and microhardness of Co-based superalloy after laser cladding are characterized by the optical microscope and the microhardness tester. The results show that due to the preheating effect of the preceding cladding process on the subsequent cladding process, the widths of the cladding layer gradually transit from the initial 4.84, 5.17, 5.88 mm to the cladding-terminal 5.28, 6.61, 6.78 mm, respectively under the effects of different laser cladding parameters. The upper surface morphology of laser cladding area is horn shape. The morphology of laser cladding is asymmetric crescent shape due to the powder feeding direction during laser cladding and the preheating effect of adjacent laser cladding on the substrate. The equiaxed grains are observed in the central area of surface cladding layer and the non-uniform dendrites are observed in the middle of inner cladding layer. Because of the non-equilibrium solidification in the process of laser cladding and the differences between heating rates and cooling ones in different sections, the hardness of the cladding layer presents a non-uniform distribution, and is always higher than the hardness of its substrate.