A new ceramic cutting fool material has been developed by means of silicon carbide whisker (SiCw) reinforcement and silicon carbide particle (SiCp) dispersion. The material has the advantage of high bending strength and fracture tougbness. Compared with the mechanical properties of Al2O3(A), Al2O3/SiCp(AP), Al2O3/SiCw(AW), Al2O3/SiCw(JX-1) and Al2O3/SiCp/SiCw(JX-2), it confirms that JX-2 composite has obvious additive effect of both reinforcing and toughening. The reinforcing and toughening mechanisms of JX-2 composite have been studied based on the analysis of thermal-expansion mismatch and the observation of microstructure, Synergistic effects of toughening and strengthening for JX-2 have been researched systematically.