In order to study the influence of oxygen flow rate on the structure, mechanical properties and tribological properties of chromium oxide films prepared by multi-arc ion plating. In this paper, a series of chromium oxide films are prepared on the surface of Inconel718 alloy by using arc ion plating technology under different oxygen flow rates (70 mL/min, 90 mL/min, 110 mL/min, 130 mL/min, 150 mL/min). Scanning electron microscope (SEM) and cold field emission scanning electron microscope (FESEM) are used to observe the surface morphology and cross-sectional morphology of the films. The phase composition and crystal structure of films are analyzed by X-ray diffraction (XRD) and Raman spectrum. The mechanical properties of the films are evaluated by scratch tester and nano-indentation. The tribological properties of the films are tested by high temperature ball disc friction and wear tester. The wear tracks of the films are observed by optical microscope, and the wear volume of the films is measured by 3D surface profilometer. With the increase of oxygen flow rate, the deposition rate of the films increases first and then decreases, and the surface of the films becomes smoother. Except that the cross-sectional morphology of the films prepared at 110 mL/min oxygen flow rate is the crystal disorderly and tightly packed, the cross-sectional morphology of the films at other oxygen flow rate are columnar crystal. As the oxygen flow rate increases, the phase composition of the films changes from Cr2O2.4 to Cr2O3, and the crystallinity of the films increases. With the increase of oxygen flow rate, the adhesion force between the films and the substrate gradually decreases, the hardness and elastic modulus of the films increase first and then decrease. The chromium oxide films deposited at 110 mL/min oxygen flow rate show excellent tribological properties in wide temperature range, the friction coefficient is about 0.49 at room temperature (25 ℃) and the friction coefficient is in the range of 0.27~0.30 at high temperature (400 ℃, 600 ℃, 800 ℃). Chromium oxide films deposited at other oxygen flow rates have a poor tribological properties at room temperature. The oxygen flow rate has a significant influence on the morphology of the surface and cross section, phase composition and mechanical properties of the chromium oxide films. The chromium oxide films deposited at 110 mL/min oxygen flow rate not only show superior mechanical properties, but also have excellent tribological properties in wide temperature range.