Abstract Metal–carbide coatings with high hardness, high wear resistance and good thermal stability are widely used for surface protection of key equipment in high-temperature environments. However, the metal binder is susceptible to oxidized spalling and wear failure during long-term operation. This leads to severe limitations in the service life and stability of the coatings. In this study, an AlFeCoNiCr–Cr3C2 coating with high-entropy alloy as metal binder was fabricated by supersonic atmospheric plasma spraying. The effect of heat treatment on the microstructure, mechanical properties and tribological responses of the coating was studied comparatively. The results suggested that heat treatment at 600 °C resulted in the formation of nano-carbides (Cr23C6), a disordered BCC and FCC phases. The evolution of the phase structure synergistically increased hardness and toughness, thereby reducing wear rate and improving the high-temperature wear resistance. The primary wear mechanisms were abrasive and oxidation wear. Wear debris consisted mainly of phases such as NiCr2O4, Al2O3, NiO and Fe2O3. Graphical Abstract