When the specific gravity stone removing machine is working, the material continuously enters the middle of the stone removing screen surface from the hopper. Due to the vibration of the screen surface and the air flow through the material layer, the porosity between the particles increases, and the material is in a fluidized state. Automatic classification is promoted. The gravel with a high specific gravity sinks into contact with the screen surface, and the grain with a small specific gravity floats to the upper level. Under the push of gravity, inertial force and continuous feeding, it slides down to the net grain outlet; while the gravel with a large specific gravity is at the outlet of the net grain. Under the action of the inertial force and air flow of the screen surface vibration system, the screen surface slides relative to the stone removal screen and moves to the selection area through the rock accumulation area. The specific gravity stone removing machine has the advantages of good stone removing effect, simple structure, small size and low energy consumption. Grain is cleaned by a specific gravity stone removal machine once. The stone removal rate is greater than 95%, the brick and mud removal rate is greater than 60%, and there are few grains lost. The cleared sand and gravel contain no more than 100 grains/kg.