The engineering application of superlubricity in dry and moist atmospheres is critical for reducing friction, wear, and economic consumption. The MoS 2/H-DLC composite can achieve superlubricity in oxygen, which can help to quickly form a MoS 2 transfer film on the surface of the counterpart at the initial sliding stage. However, the friction performances of MoS 2/H-DLC composite were still unclear in dry and moist air when these MoS 2 flakes were doped with oxygen. Regarding this problem, we constructed some MoS xO y/H-DLC composites with different degrees of oxidation, and their friction performances were investigated in both dry and moist air with relative humidities of approximately 10 %, 20 %, and 30 %. Superlubricity was achieved by the composite in dry and moist air with a relative humidity of approximately 10 %. Raman, AFM, SEM-EDS, and TEM characterizations have been conducted to reveal the composition and structures of wear scars and tracks. These results suggested that a small number of water molecules in the atmosphere could promote the formation of the MoS xO y transfer film on an Al 2O 3 ball, which was crucial for achieving superlow friction in moist air. These findings provide some helpful suggestions for obtaining superlow friction in moist air.