This study employed arc ion plating technology to prepare a series of self-organized nano-multilayer AlCrNbSiON coatings. The effects of oxygen content on the microstructure, mechanical properties, high-temperature stability, oxidation resistance, and tribological properties were systematically investigated. The results indicate that as the oxygen content increased from 0 at. % to 33.26 at. %, the coating structure transformed from columnar crystals into a nano-multilayer structure with alternating N-rich and O-rich sublayers. The as-deposited Al 0.22Cr 0.17Nb 0.05Si 0.04O 0.09N 0.43 coating with low oxygen content exhibited the highest hardness of 29.5 ± 1.18   GPa due to grain refinement strengthening and coherent interface strengthening, and showed age hardening at 900 ℃ (35.1 ± 1.8   GPa). It also achieved the lowest wear rate of 1.9×10 -7 mm 3/N·m during high-temperature tribological tests at 800 ℃. The Al 0.21Cr 0.15Nb 0.05Si 0.04O 0.33N 0.22 coating with high oxygen content demonstrated optimal fracture toughness (K c = 4.01   MPa·m 1/2) owing to its soft/hard alternating multilayer structure. Oxygen doping enhanced the high-temperature stability of the coatings by inhibiting CrN decomposition and improved oxidation resistance via forming thinner and denser oxide layers. This research confirms that appropriate oxygen doping can synergistically optimize the hardness, toughness, and high-temperature performance of the coatings, providing new insights for the design of high-performance protective coatings.