The invention discloses a cyclone separator. The cyclone separator comprises an upper cylinder and a big-end-up lower truncation cone, the diameter of the lower end of the upper cylinder is less than the diameter of the upper end of the lower truncation cone, the lower end of the upper cylinder is connected with the upper end of the lower truncation cone through an annular cover plate, the annular cover plate is provided with a plurality of blowing hole groups, and the blow holes of each of the blowing hole groups are sequentially arrayed in size. According to the invention, the accumulation of viscose impurities on the inner wall of the separator is improved, the influence of blowing to the separation efficiency of the separator is reduced, and the working efficiency of the separator is increased.