<p>The laser deposition repair test was carried out on K417G alloy using DZ125 alloy powder. The deposition specimens were subjected to aging heat treatment, and the microstructural characteristics, microhardness distribution, and friction and wear properties of the deposition and aging heat treatment specimens were analyzed. The study shows that in the deposition state, the repair zone is dominated by equiaxial crystals, with a large number of MC carbides between the dendrites and no precipitation of <i>γ</i>′ phase. Compared to the substrate, the heat-affected zone has an increased content of carbides with a relative reduction in size. After aging heat treatment, grain boundaries and grains in the repair area become more distinct, some MC carbides decompose into finer M₂₃C₆ and M₆C-type carbides, and <i>γ</i>′ phase precipitates. The average hardness of the substrate and the repair area in the deposition state were 366.5 HV_0.5 and 405.8 HV_0.5, respectively, and the average hardness of the repair area after aging heat treatment was 442.9 HV_0.5, an improvement of 9.1%. The average friction coefficients of the substrate, the deposition state repair area, and the aging heat treatment state repair area were 0.70, 0.66, and 0.60, respectively. The wear rates of the K417G alloy substrate, depositional state DZ125 alloy, and heat-treated state of the DZ125 alloy were 4.4 × 10⁻⁶, 3.4 × 10⁻⁶, and 2.2 × 10⁻⁶&#xa0;mg&#xa0;N⁻¹&#xa0;mm⁻¹, respectively. The main wear mechanisms of the substrate are abrasive wear, adhesive wear, and oxidative wear, while the wear mechanisms of the deposition state and the aging heat treatment state repaired zones are mainly mild abrasive wear, adhesive wear, and oxidative wear.</p>