It is designed for evenly discharging bulk materials from concrete bins, semi-dry bins or plastic bins, and thus to assure fully discharge and no spontaneous classification no matter it is a round, square or rectangular-sectioned bin. It is applicable to discharging the bins containing flour-like powdery material in the fields of flour, feeding stuff, chemical industry,pharmaceutical industry and so on. With the function of preventing the material from caking,it is an ideal bin discharger.