The invention discloses an ore dressing method of bauxite, and relates to the improvement of an ore dressing method during the aluminium oxide production process through an ore dressing Bayer process. The method comprises the steps of ore grinding, flotation, and picked concentrate drainage dehydration, and is characterized in that drainage filter liquor produced during the process of picked concentrate drainage dehydration is conducted to decalcification treatment, and then returns to an ore dressing circulating water system. The ore dressing method of bauxite provided by the invention has the advantages that the treatment to the filter liquor during the ore dressing process reasonably improves the picked concentrate drainage flow, and effectively improves the operation quality of the ore dressing Bayer process. The method is simple and easy to implement, and ensures that the drained filter liquor is recycled.