The invention belongs to the field of 
coating materials, and discloses a TiAlN hard 
coating and a preparing method thereof. The method comprises the steps that 
polishing ultrasonic cleaning is conducted on a hard 
alloy matrix, after blow-
drying and dust removing, the hard 
alloy matrix is placed in a film plating 
machine cavity, the cavity is heated, the temperature is increased to 400-600 DEG C, the vacuum degree of the cavity is 1-6 x 10 <-3> Pa, cooling is conducted to 300-400 DEG C, and the temperature is kept constant; inflation of Ar gas is conducted, bias pressure is loaded to a workpiece rotating stand, and the surface of the matrix is subjected to glow cleaning; the flow of the Ar gas is adjusted, the air pressure of the cavity is controlled, a Zr target is ignited through the 
cathode arc evaporative deposition method, the current of the Zr target and the bias pressure of the workpiece rotating stand are set, and 
metal ion etching is conducted on the matrix; an Ar gas valve isclosed, inflation of N2 is conducted, the air pressure of the cavity and the bias pressure of the workpiece rotating stand are adjusted, a Ti50Al50 target is ignited, the current of the Ti50Al50 target is adjusted, and the TiAlN hard 
coating is deposited on the surface of the matrix. The TiAlN hard coating has 
high heat stability and matrix bonding force.