The work aims to study the effect of MoO3/BaO composite on the tribological properties of plasma sprayed NiAl matrix composite coating at high temperature according to the oxide ionic potential and cation polarizability criterion, and clarify the high temperature lubrication mechanism of the composite coating. The composite coatings with 20, 30 and 40wt% MoO3/BaO (1∶1) were fabricated by atmospheric plasma spraying technology. The micro-hardness, bonding strength and tribological properties of composite coatings were tested by micro-hardness, universal material testing machine and friction and wear testing machine, respectively. Meanwhile, the micro-structure, phase composition, elemental distribution and morphology of the worn surface of composites coatings were in-depth analyzed by the scanning election microscopy (SEM/EDS), X-ray diffraction (XRD), micro-Raman and transmission electron microscopy (TEM). The NiAl-MoO3/BaO composite coating prepared by MoO3/BaO with lower interaction parameters and large ionic potential difference as composite lubricant effectively improved the tribological properties of NiAl coating at high temperature. Especially, the NiAl-30wt% MoO3/BaO (1∶1) composite coating had a low friction coefficient of 0.15 and a wear rate of 9.31×10–5 mm3/(N.m) at 800 ℃. The composite coating has good anti-friction performance at the temperature above 600 ℃. High temperature promotes the formation of new ternary high temperature lubricating phases BaMoO4 and NiMoO4 on the worn surface, and plays a synergistic lubrication effect on MoO3 and NiO, thus improving the friction and wear resistance of the composite coating at high temperature. At the same time, the formation of a composite oxide lubricating transfer film on the friction dual surface further reduces the wear rate of the coating.