Abstract: Different contents of Al2O3 particles were added into Ce-TZP ceramics containing SiC particles using vacuum hot-pressing sintering. The effect of Al2O3 content on mechanical properties of the complex ceramics and strength and toughness mechanism were investigated by means of XRD, SEM, EDS and mechanical tester. The results show that with the increase of Al2O3 content, the bending strength and fracture toughness increased first and then decreased, the best comprehensive properties could be obtained when the mole fraction of Al2O3 was 9%. The Al2O3 particles could refine the grains, and had deflection and bridging action on the cracks. Some Al2O3 particles embedded into ZrO2 matrix grains, formed intragranular structure, which induced the transgranular fracture and increased the strength and toughness.