<p>Surface modification is one of the effective methods to improve the stability of electrical contact. In this study, laser shock peening (LSP) was applied to pure copper, and subsequent changes in morphology, hardness, microstructure, residual stress, and fretting wear behaviors were analyzed. The relationship between debris behavior and electrical contact resistance (ECR) was examined using ECR instantaneous values against displacement (<i>R</i>-<i>D</i> curves). LSP increased surface hardness by 26%, with a maximum residual compressive stress of 171 MPa at a depth of 300 μm. Additionally, LSP reduced ECR_max and wear depth by 43.5% and 32.6%, respectively. These improvements were attributed to increased hardness, strength, and residual compressive stress due to plastic deformation and grain refinement. The main damage mechanisms were delamination with cracks and oxidation wear, and the accumulation of wear debris at the contact edge was the primary cause of electrical contact failure. As the counterbody moves from contact center to the edge, oxidized debris is continuously peeled off, accumulated, and ejected. When the counterbody reaches the contact edge, a significant amount of oxidized debris is present in the contact region, causing the instantaneous ECR to spike to its highest value. Physical models are summarized to illustrate the degradation mechanisms at different current load, and the LSP can be applied to the surface treatment of contact components in electrical connectors operating under low current levels.</p> Graphical Abstract <p></p>