An automatic material stacking device comprises a
workbench, a feeding mechanism, a turnover mechanism, a material clamping mechanism, a
transfer mechanism and a material stacking mechanism, the feeding mechanism, the turnover mechanism, the material clamping mechanism, the
transfer mechanism and the material stacking mechanism are fixed to the
workbench, the feeding end of the feeding mechanism extends to the outer side of the
workbench in a protruding mode, the turnover mechanism is arranged above the feeding mechanism, and the material stacking mechanism is arranged above the turnover mechanism. The clamping mechanism is arranged above the
transfer mechanism and the turnover mechanism, the transfer mechanism comprises a first conveying unit and a loading tray, the loading tray conveys from the input end of the first conveying unit to the output end of the first conveying unit, the loading tray is used for placing workpieces, and the stacking mechanism is arranged at the output end of the first conveying unit. The stacking mechanism comprises a lifting unit, a loading unit and a first sensor, the lifting unit is used for lifting the loading tray, the loading unit is arranged above the lifting unit and used for bearing the loading tray, and the first sensor faces the output end of the first conveying unit and used for sensing the loading tray.