Sialon ceramic tool materials were prepared by a microwave sintering technology. The influences of sintering temperature and holding time on the mechanical properties of Sialon ceramic tool materials were investigated, and the microstructure was analyzed. The results show that the tool material obtained at the sintering temperature of 1 600 ℃ and the holding time of 15 min has the optimum mechanical properties (i.e., density of 98.9%, hardness of 17.8 GPa and fracture toughness of 5.9 MPa·m1/2, respectively). In this sintering process, the material has a uniform microstructure with little internal pores, which is conducive to the improvement of its mechanical properties. The ceramic tool material with the superior mechanical properties can be obtained for a short time of heat preservation as the microwave sintering technology is used, thus improving the production efficiency.