AlON/SiC composites were synthesized by hot-pressing sintering technology using SiC and prepared AlON powder as raw materials. The influence of SiC content on relative density, hardness, bend strength and microstructure of multiphase material was studied by several testing methods, such as XRD and SEM. The strengthening mechanism of SiC was also explored in this paper. The experimental results indicated that with the addition of SiC, the bend strength of the multiphase material was obviously enhanced, comparing with AlON single phase material, and ultimately it reached 310 MPa. The best adding mass content of SiC was 8% and its strengthening mechanism was mainly thermal expansion mismatch and fine grain strengthening. As the adding mass content of SiC increased, the hardness of AlON/SiC ceramic matrix composite was increased gradually, the bend strength firstly increased and then decreased, and the main fracture way of composite was changed from intergranular fracture to transgranular fracture and finally both of the two modes of fracture occurred. This research had positive significance on deep popularization and application of AlON ceramic material.