The characteristic of the bond zone between Ni-based alloy light beam surfacing layer(SL)and base metal(BM)was investigated by scanning electron microscope,energy dispersive spectrometer and X-ray diffraction.The results show that the bond zone,which consists ofγ-Ni orγ-(Fe,Ni)planar crystal band close to SL andα-Fe bright band close to heat affected zone(HAZ),is actually the transition zone of composition and microstructure between SL and HAZ,and the metallurgical bond interface lies between theα-Fe bright band and HAZ.With the increase of light beam heat input from 2kJ/mm to 4kJ/mm,the width of the bond zone increases from 4μm to 15μm,and the morphology of bond interface changes from zigzag to straight.The formation of bond interface indicates the formation of reliable metallurgical bond between SL and BM. The characteristic of the bond zone between the nickel-based alloy light beam surfacing layer (SL) and base metal (BM) was investigated by scanning electron microscope, energy dispersive spectrometer and X-ray diffraction. The results show that the bond zone, which ofγ-Ni orγ- (Fe, Ni) planar crystal band close to SL and α-Fe bright band close to heat affected zone (HAZ), is actually the transition zone of composition and microstructure between SL and HAZ, and the metallurgical bond interface lies between the α-Fe bright band and HAZ.With the increase of light beam heat input from 2kJ / mm to 4kJ / mm, the width of the bond zone increases from 4μm to 15μm, and the morphology of the bond interface changes from zigzag to straight. The formation of bond interface indicates the formation of reliable metallurgical bond between SL and BM.