To repair damaged hydraulic columns and extend their service life, single-layer multi-pass lap cladding of an iron-based alloy was performed on a 27SiMn steel substrate using a semiconductor fiber-coupled laser. The optimal lap rate was determined based on the surface flatness quality index of the cladding layer. Subsequently, the microstructure, hardness distribution, corrosion resistance, and wear resistance of the cladding layer were investigated and analyzed. The results show that under the process parameters of laser power of 2 600 W, powder feeding rate of 15 g/min, scanning speed of 4 mm/s, and overlap rate of 40%, the cladding layer with no crack pore defect, optimal surface flatness and largest cross-sectional area of the cladding layer can be obtained. The microstructure of the cladding layer is cellular crystal, dendrite and equiaxed crystal from bottom to top. The friction coefficient is 18.2% lower than that of the substrate, and the cladding layer is oxidized wear, abrasive wear and adhesive wear. The corrosion resistance grade is 2, which is 2 grades higher than the substrate′s. The corrosion zone is intergranular corrosion, and the corrosion resistance and wear resistance are significantly improved, which provides a scientific experimental basis for laser cladding repair and strengthening hydraulic columns.