The poor high-temperature tribological performance of diamond-like carbon (DLC) films severely limits their applications. To address this issue, silicon (Si) doped DLC films with Si content ranging from 0 to 11.52 at.% were synthesized utilizing the plasma-assisted reactive magnetron sputtering technique. The influence of Si incorporation on the microstructure and mechanical properties was meticulously investigated by Raman spectroscopy, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), nanoindentation, and scratch testing. To ascertain the tribological behavior of the Si-DLC films under elevated temperature conditions, in situ high-temperature tests were conducted, spanning temperatures from ambient to 500°C. The findings indicated that distinct lubrication mechanisms prevail for Si-DLC films with varying Si content across different temperature domains. As the test temperature and Si content increased, the lubrication mechanism exhibited a gradual transitions from high-temperature induced graphitization to a particle wear regime dominated by SiC and formed SiO2 abrasive phases. The comprehensive performance of the films peaked at a Si content of 4.72 at.%, suggesting an optimal composition for high-temperature applications. It is postulated that the in-depth investigation presented herein holds considerable value for the design and fabrication of DLC films intended for use in high-temperature settings, potentially unlocking their full potential in such demanding environments.