Abstract: With Nano-TiN and SiC whisker as reinforcement phase, the silicon carbide composite ceramic sealing material was prepared by liquid phase sintering. At different sintering temperatures（1 800, 1 850, 1 900, 1 950 ℃）, the sintering properties, microstructure and mechanical properties of the composite ceramics with different mass fractions（0, 2.5%, 5.0%, 10.0%, the mass ratio of Nano-TiN to SiC whisker was 1∶1）of reinforcement phase were studied. The results with the increase of sintering temperature, the hardness and bending strength of ceramics first increased and then decreased, the fracture toughness first decreased and then increased. When the sintering temperature was 1 900 ℃, the silicon carbide composite ceramics were completely sintered, the relative density was higher, and the average grain size was smaller. When sintered at 1 900 ℃, the grain size of silicon carbide composite ceramic sealing material with reinforcement phase decreased and the grain structure was closely arranged compared with those without reinforcement phase. When the sintering temperature was 1 900 ℃ and the mass fraction of the reinforcement phase was 5.0%, the silicon carbide composite ceramics had the best comprehensive properties with relative density of 94.68%, bending strength of 429.51 MPa, hardness of 17.14 GPa, fracture toughness of 4.32 MPa·m^1/2.