The change of temperature will lead to the presence and content of water molecules at the friction interface, which in turn affects the change of humidity in the friction interface area. In this work, the tribological behavior of the a-C:H:Si:O film against GCr15 ball at RT-200 ℃ were studied. Through friction interface analyses, variable temperature friction test and comparison of friction coefficient under different relative humidities, the temperature-induced tribological mechanism was expounded. It is found that the turning temperature of the friction behavior change is greatly affected by the ambient humidity, which changes the presence state of the transfer layer and affects the friction performance.