Abstract: In this study, MoN coating was deposited on 9Cr18 steel substrate and Si wafer by high power pulsed magnetron sputtering. The effects of different bias voltages on the microstructure, mechanical properties and tribological properties of MoN coatings were systematically studied, and the coatings with excellent wear resistance were selected. The surface and cross-section morphology of the coating were analyzed by field emission scanning electron microscopy. The crystal phase structure of the coatings were analyzed by X-ray diffractometer. The hardness and elastic modulus of the coating were measured by nanoindenter. The adhesion of coating was analyzed by scratch tester. Three-dimensional profilometer was used to analyze the wear depth of MoN coating. The friction and wear properties of the coatings were evaluated by CSM friction and wear tester. The results showed that: in terms of microstructure, the surface of MoN coating deposited by HiPIMS technology was compact and smooth, and there were no obvious defects such as large particles and microcracks. With the increase of bias voltage, the ion bombardment on the substrate was enhanced, which made the grown columnar crystal interrupted, the coating changed from columnar crystal structure to compact and featureless crystal structure. And the phase structure was dominated by face-centered cubic Mo₂N phase, with a small amount of Mo phase structure. In terms of mechanical properties, with the increase of bias voltage, the ion bombardment effect increased, and the hardness of the coating gradually increased. When the bias voltage was 160 V, the hardness of the coating was the highest, reaching 33 GPa. The elastic modulus of MoN coating showed a trend of increasing at first and then decreasing, when the bias voltage was 120 V, the maximum elastic modulus was 357.7 GPa. The corresponding increase of H/E and H³/E² values also represented the enhancement of wear resistance of MoN coating. MoN coating deposited by HiPIMS method all showed good coating-substrate adhesion (about 60 N). However, with the increase of bias voltage, the residual stress of MoN coating increased, and when the bias voltage was 160 V, the bonding force decreased to about 58 N. In terms of tribological properties, there was no obvious difference in friction coefficient of MoN coating deposited under different bias voltages, and the average friction coefficient of coating deposited under 120 V bias voltage was the lowest, which was 0.24. In terms of wear rate, the wear rate of S120 and S160 samples was two orders of magnitude lower than that of S40 and S80 samples. This was because the energy bombardment carried by plasma was weak under low bias voltage, the coating deposited on the substrate had low bonding strength and poor compactness. Moreover, the columnar loose structure of MoN coating leads to its low hardness, poor crack propagation resistance and wear resistance, and it was easier to produce microcracks and local spalling during friction. By adjusting and increasing the appropriate bias voltage, the coating structure was denser, and the coating had no crack defects. Meanwhile, with the enhancement of ion bombardment effect, the bonding force and hardness of the coating were increased. The anti-plastic deformation ability of the coating was enhanced, which effectively inhibited the generation and expansion of cracks, and the abrasive particles peeled off during friction were correspondingly reduced. The wear marks of the coating were relatively narrow and shallow, among them, the lowest wear rate of S160 was 1.4×10⁻⁸ mm³/(N·m).