To address the temperature limitations of MAX phase and improve the temperature adaptability of Ni-based coating, a NiCrAlY-Ti 3AlC 2-SnBiAg-Mo composite coating was fabricated via atmospheric plasma spraying. The tribological properties of the composite coating were evaluated over a wide temperature range from room temperature (RT) to 800 °C using reciprocating friction testing, and its wear mechanism was comprehensively analyzed through scanning electron microscope (SEM), X-ray diffraction (XRD), Raman, and X-ray photoelectron spectroscopy (XPS). Results demonstrate that SnBiAg incorporation effectively enhances coating density, reduces porosity, enhances structural homogeneity, and refines grain size. At RT, SnBiAg alloy flows into cracks along with the sliding of friction pairs, exhibiting a certain degree of crack healing capability. The composite coating (20 wt% SnBiAg) exhibited optimal wear resistance with the wear rate 1.5 × 10 −5 mm 3/(N·m) at 600 °C, and its thermal cycling tribological performance was the relative best. This is primarily attributed to the synergistic lubrication effect of MAX phases, various binary metal oxides, and a small amount of high-temperature lubricating phases such as NiMoO 4, Ag 2MoO 4, and Bi 2MoO 6. Meanwhile, the SnBiAg-Mo alloy effectively suppresses the oxidative decomposition of Ti 3AlC 2 at high temperature, which results in the transformation of the primary Ti oxide from TiO 2 to Ti 2O 3 with enhanced interlayer bonding strength.