The invention discloses a nonferrous metal alloy-toughened aluminum nitride ceramic-based composite material and a preparation method thereof. An aluminum nitride blank comprises aluminum nitride, yttrium oxide, alumina and carbon black according to a weight part ratio. The preparation method comprises the following steps of heating in a nitrogen atmosphere to obtain an aluminum nitride blank having porosity less than 43%, heating a die-casting machine, heating a copper alloy until melting, pouring the melted copper alloy into a cavity for receiving the aluminum nitride blank, pressing the melted copper alloy into the aluminum nitride blank by a pressing head, cooling a casted block, and separating the casted block from a mold. The nonferrous metal alloy-toughened aluminum nitride ceramic-based composite material has the characteristics of high elasticity modulus, high strength, high hardness, excellent frictional property and low thermal expansion coefficient. Compared with the traditional aluminum nitride ceramic materials, the nonferrous metal alloy-toughened aluminum nitride ceramic-based composite material has higher fracture toughness, and can be widely used for friction and wearing structural members of electromechanical special equipment, heat-resistant corrosion-resistant structural members of pressure-bearing special equipment, aerospace structural members and automobile structural members.