The principle of 5XZJ-5 Specific Gravity Cleaning Machine is in fluidizing process the graininess material will produce proportion segregation phenomenon, by adjusting wind pressure, amplitude and other parameter, interlayer was produced between materials, large proportion sink, small proportion float up, after dropped into falling area, drain out different proportion material from different place. This machine is suitable for wipe out scurf grain, rice sprout, damaged by worms, smut, grain with shell and light impurity and small than 2mm tiny impurity. The materials screened by this machine featured high increase of thousand seed weight, germination percentage, cleanliness, neatness.