Abstract:The laser repair experiment of 1Cr17Ni2 stainless steel was carried out with GH4169 alloy. The test discussed that how different scanning speeds influenced the microstructure and microhardness. With the rise of scanning speed, the quality and mechanical properties have been obviously ameliorated, while the microstructure and microhardness of the cladding layer will be damaged at too high scanning speed. When the scanning speed is 0.012m/s, the grain structure is excellent, and the average solidity is 9.78% higher than the matrix. The average mass fraction of Nb in the dendrite dry in the cladding area increases to 5.58% and the average volume fraction of Laves phase decreases to 2.3%. The properties are coordinated with the matrix, and the mechanical properties are good. The microstructure after repair is mainly formed of γ , γ′, γ″ and δ, the grain structure is formed by parallel columnar crystal structure without obvious welding defects, and the cladding layer forms a close metallurgical bond with the matrix.