Abstract: The fine−grained tailings aggregates are prone to consolidation during long−term storage, which reduces the effective storage volume of thickener and causes the formation of preferential flow channels during sand discharge, leading to a decrease in the mass concentration of the discharged sand and even fluctuations in the underflow concentration and blockage of the discharge port. To address the issue of activated underflow discharge of thickened tailings in rake−less paste thickeners, a small−scale vibrating sand discharge experimental setup was developed. Experiments were conducted to investigate the effect of vibrating rods on tailings slurry, exploring how vibration enhances slurry activation and its influencing characteristics. The experimental results show that the activation range induced by vibration is closely related to vibration frequency, inertia, and tailings mass concentration. The vibration effect facilitates underflow discharge, reducing the sand discharge time by 47.6% compared to non−vibration discharge, with higher frequencies yielding better results. The sand discharge time increases with the decrease in vibration inertia, and greater inertia effectively activates settled tailings and improves discharge performance. As the mass concentration of the slurry increases, the final discharge time also increases, but discharge efficiency significantly declines when the concentration exceeds 50%. The vibration effect exerts a certain thixotropic activation effect on the initial discharge of tailings that have been stored for a long time, but its effectiveness diminishes markedly after storage time exceeds 3 days. The research results reveal the mechanism of steady−state activation and discharge of high−mass−concentration tailings slurry under mechanical vibration, providing a theoretical basis for developing new thickening equipment with vibration−assisted functionality.