The microstructures and mechanical properties of SiCp/2024 composite processed by repetitive upsetting and extrusion (RUE) were investigated through tensile testing, optional microscopy(OM),scanning election microscopy(SEM) and transmission election microscopy(TEM). The results showed that the matrix was effectively refined during the repetitive deformation, the distribution of SiC particles was improved, and some SiC particles were broken by shear force. Due to alternating shear deformation, the dislocation on the matrix was reorganized and annihilated, and then some small sub-grains were formed. Compared with the as-extruded SiCp/2024 composite, the tensile strength increased from 271 MPa to 378 MPa after 4 passes, and the yield strength increased from 203 MPa to 260 MPa. The fracture of the composite after RUE mainly resulted from interfacial debonding and SiC particles breakage.