A cosmetic brush fixing apparatus includes: an outer tubular body, a fixing ring, and a retainer connecting the outer tubular body with the fixing ring. The fixing ring is connected with a silicone disc which is formed with an insertion opening for mounting a cosmetic brush. A technical key point is that the fixing apparatus is for securing a hand-held part of the cosmetic brush, by using a motor to drive the fixing apparatus to rotate, bristles on the cosmetic brush are driven to rotate, which facilitates the cleaning of the cosmetic brush. By use of cutting grooves formed in the silicone disc, it can adapt to most of cosmetic brushes. Limiting grooves can make a circle center of a cross-section of the cosmetic brush and a circle center of the silicone disc basically coincide with each other when the cosmetic brush is inserted into the silicone disc.