Suction type gravity grading stoner is mainly applicable for grain processing factories and feed processing enterprises. It is used for separation of pebbles from paddy, wheat, rice, soybean, corn , sesame, rapeseed, malt etc. It can also do the same to other granular materials. It is an advanced equipment for the modern grain processing enterprises. It utilizes the characteristics of different specific gravity and suspended velocity of both grain and impurity. It is backed by air draft action that penetrates the gap of grain current and granular materials. It pressurizes the grain , pebble and heavy impurity to the level. They then move to opposite directions under the reciprocating movement of the sorting sieves and thus separate pebbles from the grain. It applies transmission machinism of vibration motor with firm: smooth and reliable operation ,stable technologival properties, low noise, no overflow of dust ,convenient operation and repair etc.