Al₂O₃/Al₂O₃ composite was prepared by slurry infiltration method in one processing cycle using Nextel 720 alumina fiber as reinforcement in order to facilitate the preparation of large components. Physical and mechanical properties of the composite were evaluated and the cross section and microstructure were studied by optical microscope and SEM. The results show that the bulk density of Al₂O₃/Al₂O₃ composite is 2.64 g/cm³ and the apparent porosity is 26%， porous nature of the matrix is evident. The transverse thermal conductivity from room temperature to 1 200 ℃ is 3.49 to 2.04 W/（m·K） for the prepared composite. The CTE in thickness direction from 200 ℃ to 1 200 ℃ is 4.7×10^-6 to 7.1×10^-6/K. The in-plane tensile strength at room temperature， 1 100 ℃ and 1 200 ℃ are 202.4 MPa， 222.4 MPa and 228.4 MPa，respectively. It is clearly observed that many fibers are pulled out of the ceramic matrix from the optical micrographs and SEM image of fracture surface of tensile specimen. Flexure strength of Al₂O₃/Al₂O₃ composite at room temperature is 200.5 MPa， and the sample shows ductile fracture. Interlaminar shear strength of Al₂O₃/Al₂O₃ composite is 21.0 MPa. The main properties of the prepared materials are equivalent to the same type of material from ATK-COI Ceramic， USA， and some mechanical properties are better.