Molybdenum diboride films are anticipated to be used in cutting applications as a potential replacement for nitride coatings due to their high hardness and good high-temperature stability. However, the films undergo severe oxidation at 600 °C, which does not guarantee good wear resistance. The addition of Cr element is chosen to improve the film's oxidation resistance, which in turn improves the film's friction and wear performance at higher temperatures. The Mo-Cr-B films were prepared by magnetron sputtering by changing Cr target current. The oxidation properties of the films at 600 °C and the tribological performance and the wear mechanism at 25 °C, 400 °C and 600 °C were investigated. The results reveal that the MoB2-z film and Cr-alloyed MoB2-z films have higher hardness (>30 Gpa). And the Mo0.67Cr0.33B2-z film and Mo0.51Cr0.49B2-z film exhibit much greater oxidation resistance at 600 °C than do MoB2-z film and Mo0.79Cr0.21B2-z film. The Mo0.67Cr0.33B2-z film demonstrates good wear resistance at 25 °C, 400 °C and 600 °C. Especially at 600 °C, the Mo0.67Cr0.33B2-z film clearly outperforms the MoB2-z film in terms of wear resistance.