The invention discloses hydrolysis-resisting aluminum nitride powder and a preparation method thereof. The hydrolysis-resisting aluminum nitride powder is prepared by carrying out covering treatment on surfaces of aluminum nitride powder particles through an organic acid and a coupling agent, wherein the content of the organic acid is 1 to 15 weight percent, and the content of the coupling agent is 0.5 to 20 weight percent. An experiment proves that at room temperature, the aluminum nitride powder prepared by the preparation method is immersed into water and can keep unhydrolyzed for one weekor longer than one week; at 80 DEG C, the hydrolysis-resisting aluminum nitride powder prepared by the preparation method can stably exist in water for at least 72h without any hydrolysis. The problemthat aluminum nitride powder is not easy to store and apply, caused by the fact that the aluminum nitride powder is easy to hydrolyze, is effectively solved. Furthermore, the advantages of simple technological operation, low raw material price, low production cost, wide application range, easiness for realizing industrial production and the like are also achieved; the industrial application valueis remarkable, and large-scale industrial application of aluminum nitride is facilitated.