The present invention discloses the active substances for preventing hearing deterioration, its preparation method, the pharmaceutical composition containing the active substances, and the preparation method of the pharmaceutical composition. The preparation method of the active substances is performed by plate cultivation, flask cultivation and fermentation tank cultivation, to obtain the active substances of Hericium erinaceus mycelia in powder form. The powder of H. erinaceus mycelia is proved to have the effect of preventing hearing deterioration.