<p>Insufficient wear resistance of as-cast Cu-Sn-Bi alloys constrains their application potential, and tailoring the microstructure and the distribution of the Bi-rich phase offers an effective strategy to enhance tribological performance. In this work, the mechanical vibration with different frequencies were applied during solidification process to investigate its effect on the solidification microstructure evolution and Bi-rich phase distribution of Cu-12Sn-6Bi-2Ni alloy. The mechanical and tribological properties of the samples were evaluated, while finite element analysis was employed to elucidate the influence of vibration on the melt behavior. The results indicate that the application of mechanical vibration can significantly reduce the area of the columnar grain zone and promote dendrite fragmentation. Bi-rich phase aggregates and coarsens at low frequencies, while becoming fine and dispersed with increasing vibration frequencies. Sample prepared under 50&#xa0;Hz mechanical vibration exhibits an 18% reduction in wear rate compared to that without mechanical vibration, and the thickness of the tribologically affected zone also decreases. Finite element analysis results reveal that vibration-induced flow homogenizes the temperature field and inhibits columnar grain growth. This work demonstrates that introducing mechanical vibration into the melt effectively optimizes the microstructure of Cu-Sn-Bi alloys, offering a reproducible methodology for the processing of similar multi-component systems.</p>