SiC_P/Mg₉₄Zn₅Y₁ composites with 0.5wt%~2.0wt% SiC_p were prepared by the casting method. The mechanical properties and damping capacities of the composites were investigated. The microstructure and phase components of the composites were analyzed via the scanning electron microscopy and X-ray diffraction. Results show that after the addition of SiC_p into the matrix, the SiC_p is evenly distributed in the matrix, which refines the microstructure of the composite. The SiC_p/Mg₉₄Zn₅Y₁ composites contain the α-Mg, I-phase (quasicrystal phase), and SiC_p phase. The damping capacities and mechanical properties of the SiC_p/Mg₉₄Zn₅Y₁ composites were evaluated by the dynamic mechanical analyzer and an AG-X testing machine, respectively. The mechanical properties of the composites are better than those of the original Mg₉₄Zn₅Y₁ alloy. The 1.0wt% SiC_p/Mg₉₄Zn₅Y₁ composite exhibits the compressive strength of 350 MPa. The damping properties of all the composites are much higher than those of the parent alloy. The optimal damping capacity is achieved when the composite contains 0.5wt% SiC_p. Moreover, according to the efficiency coefficient method, the 1.0wt% SiC_p/Mg₉₄Zn₅Y₁ composite has the optimal comprehensive properties.