Studies show that Ti(n?2)Cr2O(2n?1) phase which was similar to Magnéli phase exhibits excellent tribological properties if 6≤n≤9. In order to deeply explore the relationship between structure and mechanical and tribological properties of double metal oxide, double metal oxide films with different CrxTiyOz structures were designed and fabricated by adopting the technology of multi-arc ion plating. Effects of different structures on mechanical and tribological properties of the as-deposited and annealed films were investigated. With the decrease of the Ti content, quantity and size of large particles in original film decreased, film-substrate cohesion first increased and then decreased, friction coefficient changed slightly to nearly 0.3 and wear rate was 3×10?8 mm3/(N?m). Crystallinity of the films increased after annealing. With the decreased of Ti content, film hardness increased, the film-substrate cohesion increased, and both the friction coefficient and wear rate decreased gradually. Cr2Ti4O11, CrTiO3 and Cr2O3 composite phases were produced if the annealed films had high Ti content, thus leading to loosen film structure, and poor mechanical and tribological properties.