Diamond films with different methane concentrations were deposited on silicon carbide substrate by hot filament chemical vapor deposition (HFCVD). The morphology and phase of the diamond films were analyzed using field emission scanning electron microscope, Raman spectrometer, and atomic force microscope. The friction coefficient and wear rate of all the diamond films were calculated in dry sliding condition by the reciprocating friction experiment. Phase analysis and friction experiment results were used to analyze the influence of methane concentration on diamond film tribological properties. Results show that the quality of diamond crystals deteriorates with the increase of methane concentration, and the film changes from microcrystalline to nanocrystalline. The diamond film with 3% methane concentration has better wear resistance and the wear rate is 2.2×10-7 mm3/mN; the friction coefficient of diamond films prepared at 5% methane concentration is lower (0.032), and the wear rate is 5.7×10-7 mm3/mN. Compared with the silicon carbide substrate (9.89×10-5 mm3/mN), the wear rate of the diamond film is improved by two orders of magnitude, which significantly improves the wear resistance of the silicon carbide substrate.