[Objective] To clarify the impact of vegetation restoration duration on runoff and sediment characteristics in high-altitude mining waste dump slopes, providing scientific basis for subsequent efficient artificial vegetation restoration and soil and water conservation efforts. [Methods] Using slopes of waste rock dumps at different restoration stages in the Delni Copper Mine area, Golok Tibetan Autonomous Prefecture, Qinghai Province, as the study subjects, the influencing mechanism of vegetation restoration duration on runoff and sediment production characteristics was analyzed through plant plot surveys and artificial rainfall simulation tests. [Results] (1) As the duration of vegetation restoration increased, key indicators of plant growth—represented by cover, litterfall quantity, and aboveground biomass—showed a significant upward trend (P<0.05). Additionally, species diversity and plant root systems gradually exhibited a stepwise recovery pattern of “quantity-quality-structure.” (2) The ranking of soil physical and mechanical properties on the slopes of high-altitude mining waste dumps showed a positive correlation with vegetation restoration duration. Specifically, properties gradually improved over time: soil density, moisture content, compaction, and cohesion all increased, while bulk density and porosity decreased. (3) The period 9~15 minutes after rainfall represents the sensitive phase for soil erosion on high-altitude mining waste dump slopes. Sediment yield exhibits an initial increase followed by a decrease over rainfall duration, while runoff yield shows a sharp initial increase followed by stable fluctuations over the same period. Sediment yield, runoff yield, runoff coefficient, and sediment concentration all showed positive correlations with rainfall intensity but negative correlations with vegetation restoration duration. Both rainfall intensity and vegetation restoration duration are significant factors influencing soil erosion. (4) During plant restoration on high-altitude mining waste dump slopes, root surface area density (P<0.01), Shannon-Wiener index (P<0.05), and porosity (P<0.05) are key environmental factors influencing soil erosion. Plant community characteristics (path coefficient = -0.892) and plant root characteristics (path coefficient = -0.733) directly or indirectly influence soil erosion through soil physical and mechanical properties (path coefficient = -0.839). [Conclusion] The duration of vegetation restoration effectively enhances the erosion resistance of slopes in high-altitude mining waste dumps by improving and optimizing soil physical and mechanical properties.