SiC particle reinforced aluminum matrix (SiCp/Al) composites contain irregular silicon carbide particles, causing a large number of non ideal cross-sections in the material, which makes it difficult to remove the surface of the material effectively. Simulation analysis and experimental verification of surface removal of SiCp/Al composite with variable cutting depth were carried out, in order to reveal the mechanism of material removal. Results show that the interface failure has an important impact on surface formation and there are removal processes such as aluminum alloy matrix tearing, interface separating; silicon carbide particles exposing, crack propagation, breaking and falling off, pressing into aluminum alloy matrix, debris sliding against the material surface, etc. The large area of the silicon carbide particles crushing and falling off, causes pit defect and the material is subjected to secondary cutting under the tool push, so that the surface of the aluminum matrix forms non-continuous cracks. In SiCp/Al composites, the actual cutting depth is less than the nominal cutting depth due to the existence of aluminum alloy matrix. Research in this paper can provide some references for the study of removal mechanism and processing of SiCp/Al composites.