Featured with the dense and stability under high temperature, a ZrSiO4-aluminosilicate glass coating for the carbon/carbon composites was designed and prepared via a slurry painting-sintering process. The molten aluminosilicate glass can fill the crevices and cracks to improve the compactness, and play a self-healing role to restrain the propagation of the cracks caused by thermal mismatch under the high temperature. Furthermore, it has high infrared emissivity, which is helpful for cooling of composites to improve the antioxidant capacity. This coating has high antioxidation capability with a mass loss of 23.8 g/m2 for substrates at 1773 K for 20 h.