SiC multiphase ceramics were prepared via spark plasma sintering using AlN and TiB 2 as the second phase and Y 2O 3 as a sintering additive. The effects of TiB 2 content (10 vol.% and 20 vol.%) and sintering temperature (1900 °C to 2100 °C) on the phase composition, microstructure, and mechanical and tribological properties of SiC multiphase ceramics were investigated. The results showed that Y 2O 3 reacts with Al 2O 3 on the surface of AlN to form the intercrystalline phase Y 4Al 2O 9 (YAM), which promotes the densification of the multiphase ceramics. The highest density of SiC multiphase ceramics was achieved at 10 vol.% TiB 2 content. Moreover, TiB 2 and SiC exhibited good interfacial compatibility. In turn, a thin solid-solution layer (~50 nm) was formed by SiC and AlN at the interface. The periodic structure of SiC prevented the dislocation movement and inhibited the base plane slip. The most optimal mechanic characteristics (a density of 98.3%, hardness of 28 GPa, fracture toughness of 5.7 MPa·m 1/2, and bending strength of 553 MPa) were attained at the TiB 2 content of 10 vol.%. The specific wear rates of SiC multiphase ceramics were (4–8) × 10 −5 mm 3/N·m at 25 °C and 2.5 × 10 −5 mm 3/N·m at 600 °C. The wear mechanism changed from abrasion at 25 °C to a tribo-chemical reaction at 600 °C. Therefore, adding lubricious oxides of TiB 2 is beneficial for the improvement in wear resistance of SiC ceramics at 600 °C.