A method for repairing damage on a non-friction surface of a carbon brake disc of an aircraft, includes: removal of a damaged region, cutting of a repair material, anti-oxidation modification of the repair material, bonding and curing, and high-temperature heat treatment. The anti-oxidation modification is performed on the repair material without affecting the mechanical properties of the repair material, which improves the anti-oxidation ability of the repair zone and avoids the preparation of an anti-oxidation coating. In this way, only the damage on the non-friction surface is repaired, and there is little effect on the mechanical properties, friction and wear properties and thermal conductivity of the carbon-carbon composite material.