Abstract: The structure of the toothed-roll of a sizing crusher is key influential factor of the crusher′s working performance. The crusher working at a limestone quarry Xinjiang Uyur Autonomous Region was found to have the trouble that the crushed product was not up to the standard in size. To deal with this situation, the clearance between rolls was adjusted in the early stage, but the product was mostly in a bar shape with an irregular size. Through analysis of the structure of the roll, a cost-effective optimization scheme is proposed as follows: readjusting the arrangement order of the toothed plates of one of the rolls and changing the internal rotation of two rollers from a V form to a parallel form. Optimizing the roll and toothed plate by adding small teeth in front of the crushing teeth to narrow the space in front of the crushing teeth and allow the small teeth to play the crushing role; welding the retaining plates onto the side dispersal toothed plates to reduce the clearance between the toothed plate and the crushing roll. Trough optimization, the >80 mm large pieces in the crushed product is seen to be basically eliminated, with the rate of the product in qualified size being greatly increased from formerly 67% to 78%. The optimization work made has led to significant improvement of the performance of the crusher and provides a certain data support for the improvement or development of the same series crusher.