<p>316L stainless steel components fabricated by selective laser melting (SLM) suffer from surface defects and insufficient wear resistance, which limit their use in critical tribological applications. To overcome the limitations of conventional ultrasonic shot peening, which mainly relies on the kinetic impact of shot media, this study proposes a powder-embedded ultrasonic shot peening method. SLM 316L stainless steel was treated by ultrasonic shot peening for 3&#xa0;min, and TiO₂ and Cr₂O₃ ceramic powders were introduced into the peening medium to exploit the synergistic effect of shot impact and powder embedding and to form a ceramic particle-reinforced composite modified layer. The microstructure and mechanical properties of the modified layers were characterized using SEM, EDS, XRD, EBSD, and nanoindentation. Reciprocating friction-wear tests were performed under normal loads of 10–20&#xa0;N to evaluate the tribological performance of the modified layers. The results show that, compared with conventional ultrasonic shot peening, the powder-embedded ultrasonic shot peening method more effectively refines surface grains, increases surface hardness, and exhibits improved resistance to plastic deformation, while simultaneously achieving lower friction coefficients and wear rates. These findings indicate that the synergistic effects of particle reinforcement and grain refinement significantly enhance the macroscopic mechanical properties and wear resistance of SLM 316L stainless steel.</p>