Abstract: Ag-Cu-MoS₂ composites with different weight friction of Cu (2%~4%) were prepared by powder metallurgy. The mechanical performance and vacuum electrical/wear behavior were investigated. The results show that the composites had a higher bending strength and brinell hardness at Cu weight friction of 3.0% to 4.0%, and a lower contact voltage and electrical noise at Cu weight friction of 2.5% to 3.0%. Furthermore, the contact voltage and electrical noise increased as sliding velocity increased. During the sliding against Ag alloy under current-loading in vacuum, all the Ag-Cu-MoS₂ brushes exhibited relatively low wear rates at a range of 1×10^–14~2.5×10^–14 m³/(N·m), and the main wear mechanism was adhesive wear and fatigue wear.