A novel method of the combination of high energy milling and hot pressing was adapted to fabricate dense titanium nitride-alumina (TiN/Al2O3) in situ composites using Ti, Al and TiO2 as raw materials. Full dense and pure TiN/Al2O3 composites were fabricated at 1300 °C for 1 h under 10 MPa. The composition, microstructure and mechanical properties of the as-fabricated products were investigated. The results show that the synthesized TiN/Al2O3 composites possess high purity. The TiN/Al2O3 composites have a good combination of mechanical properties of hardness of 18.0 GPa, the flexural strength of 500 MPa, and the fracture toughness (KIC) of 5.2 MPa•m1/2. The strengthening and toughening mechanisms are also discussed.