The invention discloses a method for improving settling separation performance of bauxite slurry. The method comprises the following step: settling and separating bauxite slurry which is dissolved at a high pressure in a separating and settling tank, wherein an overflow clean liquid of the separating and settling tank is divided into two paths, one of which is led to a coarse liquid tank of a leaf filtering system while the other of which is lead to dilute the bauxite slurry which is dissolved at the high pressure, and a bottom flow of the separating and settling tank is led to a washing and settling tank. According to the method disclosed by the invention, the settling speed of the bauxite slurry is accelerated and the settling and separating effect is obviously improved.