The high hardness and chemical inertness of SiC hinder its efficient material removal and surface planarization during chemical mechanical polishing (CMP). Although Fenton-like reactions have been explored to promote SiC surface oxidation, conventional physically mixed catalyst-abrasive systems often suffer from poor dispersion and require external fields to enhance the catalytic reaction. The novelty of this work lies in the construction of integrated Cu_xO-CeO₂/Al₂O₃ composite abrasives, in which Cu_xO-CeO₂ Fenton-like catalysts are directly supported on commercial Al₂O₃ abrasives to couple catalytic oxidation and mechanical abrasion without external-field assistance. In SiC polishing, the composite abrasives deliver a material removal rate of 538.45 nm/h and a surface roughness of 0.629 nm over 50 × 50 μm², with a damaged layer thickness of 2.3 nm. CeO₂, owing to its low Mohs hardness and low elastic modulus, improves the wetting and frictional properties of the composite abrasives and promotes the formation of active Cu⁺ species. The Cu⁺ species catalyze the decomposition of H₂O₂ to generate highly oxidative ·OH radicals, which promote SiC surface oxidation and facilitate its subsequent removal by Al₂O₃ abrasives. This synergistic mechanism involving Fenton-like oxidation and mechanical abrasion was investigated by combining transmission electron microscopy and time-of-flight secondary ion mass spectrometry with electron paramagnetic resonance spectroscopy for the identification of reactive radicals.