SiCp/Gr/ZL101 aluminum-based composites is prepared by semi-solid stirring and gravity pouring method. The effects of SiCp/Gr with different volume fractions on the microstructure and property of aluminum-based composites are studied by means of microstructure observation, tensile test, fracture scanning and analysis and damping capacity test and analysis. The results show that the primary phase α-Al of ZL101 alloy prepared by semi-solid stirring and gravity pouring method is fragmented dentrite，along with the rising SiCp volume fractions, the tensile strength of the composites first increases and then decreases while its elongation gradually decreases, the maximum tensile strength of the material can reach to 168MPa, up to 16% than that of ZL101 alloy, the fracture morphology is obvious brittle fracture. They also show that the addition of SiCp and Gr improves the damping capacity of ZL101alloy, the internal dissipation Q-1 of the composites is obviously higher than that of matrix alloy and gradually increases along with the rising SiCp volume fractions. The damping mechanism of the composites is mainly the combined effects of both dislocation damping and interfacial damping.