The present invention discloses an alumina fiber reinforced alumina ceramic matrix composite and a preparation method thereof, the alumina fiber reinforced alumina ceramic matrix composite is characterized by comprising the following raw materials by weight: 40-60 parts of alumina, 20-30 parts of clay, 10-15 parts of modified alumina fiber, 2-3 parts of antimony sulfide, 1-3 parts of beryllium oxide, 0.03-0.05 part of methyl ethyl ketone peroxide, 3-5 parts of vinyl acetate, 0.2-0.4 part of silane coupling agent KH550, 1-2 parts of microcrystalline wax, 1-2 parts of carboxymethyl cellulose, 20-30 parts of ethanol, and 30-40 parts of deionized water; the antioxidant treated alumina fiber added in the alumina fiber reinforced alumina ceramic matrix composite is used as a ceramic reinforcing phase, and has the characteristics of ceramic toughness reinforcing properties, mechanical properties, abrasion resistance, hardness and high temperature resistance, the gel casting technology used in the method can reduce the production cost, and improve the material integrity and machinability, and any shape and size of ceramic structural workpieces can be convenient to produce.