5Y-TZP/TiB₂ nano-composite ceramic material was prepared by vacuum hot pressing technique, study oh the effect of two-step sintering on the microstructure and mechanical properties of the composite. 5Y-TZP/TiB₂ nano-composite ceramic materials were obtained from 80% ZrO₂(as stabilized 5mol%Y₂O₃), 10% TiB₂, 5% Al₂O₃, 2% MgO, 2% Mo and 1% Ni. Two-step sintering has been carried out for two different sintering times: 120 minutes at 1100 °C and 60 minutes at 1450 °C。The results have shown that with the two-step sintering could be benefit to make the m-ZrO₂ to the t-ZrO₂, densification, refinement and strengthening. Compared with the ordinary materials, the flexural strength, fracture toughness and hardness of 5Y-TZP/TiB₂ nano-composite ceramic material was 1023 MPa, 11.33 MPa?m_1/2 and 13.91 GPa, increased by 12.2%、17.9% and 13.5%, respectively. Toughening and strengthen mechanism of 5Y-TZP/TiB₂ nanocomposite ceramic material including crack deflection and crack bridging, and the trans-granular fracture mode was occurred.