Abstract: In order to study the relationship between misplaced material and the shape screen aperture in moving sieve jig,the misplaced material’s formation,the screen bar and screen plate’s processing and manufacturing and the open area are analyzed to square,oblique and curve screen plate here,then put forward a new idea of sieve plate adopting arc-wavy screen aperture. The results show that the arc-wavy screen aperture has superiority in reducing misplaced material etc.