Abstract: In order to repair aircraft engine blades (K417G) of the casting defects and damage. Ni-based alloy powder (RCF-201) was cladded on a nickel-based superalloy K417G substrate by a 500W-IPG fiber laser cladding system. The microstructure and composition of the surfacing layer were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), electron probe microanalysis (EPMA) and energy dispersive spectrometer (EDS), the hardness distribution of surfacing layer was analyzed by microhardness tester, the creep properties of surfacing layer was analyzed by high temperature creep testing machine. The results show that, the microstructure of the cladding layer from the fusion line to the surface consists of plane crystal, columnar crystal and equiaxed crystal; The microstructure of the cladding layer is hypoeutectic structure, the primary crystal phase is Ni-rich solid solution and the eutectic structure is γ-Ni + Cr₇C₃ + Cr₂₃C₆ + (Mo_0.54, Ti_0.46) C; The hardness of the cladding layer is about 650 HV, which is about 1.86 times the hardness of the base metal (350 HV); Under the condition of 950℃/235 MPa, the creep life of laser cladding specimen is about 26.17 h and the fracture position is located at the base metal.