This study develops a plasma sprayed nickel-based composite coating incorporating Ti 3AlC 2 and Bi 2O 3 (Ni-10/20   wt.%Ti 3AlC 2-10/20   wt.%Bi 2O 3) as reinforcing and lubricating additives to synergistically enhance mechanical and tribological properties throughout a broad temperature range. The effects of increasing additive contents on microstructure evolution and mechanical behaviors of the composite coatings are investigated. Results show that the coatings are primarily composed of γ-Ni, Bi 2O 3, and Ti 3AlC 2, along with trace amounts of TiC and borides. The Ti 3AlC 2 additions improves microhardness while an increase in Bi 2O 3 content results in concurrent decline for both microhardness and interfacial bonding strength due to the heightened porosity. The tribological performance evaluated from room temperature (RT) to 800°Cdemonstrates a significant reduction in friction coefficients by 17.9–33.7% at 800°C in comparison to Ni-(10/20   wt.%)Ti 3AlC 2 coatings. Among all compositions, Ni-20 wt.%Ti 3AlC 2-20 wt.%Bi 2O 3 exhibits the optimal wear resistance across the entire temperature range, benefiting from the synergistic lubricating effect of Bi 2O 3 and Ti 3AlC 2. Complementary wear mechanisms analysis indicates the formation of a tribo-oxidatively generated layer composed of NiO, Bi 2O 3, Al 2O 3, and TiO 2. Molten Bi 2O 3 enhances the density and viscoelasticity of this layer, thereby improving lubricity and contributing to reduced wear at elevated temperatures.