The invention relates to a bulk material bin bottom loosening and cleaning device which comprises a fixed end, a screw rack body, a first driving device and a second driving device, wherein the fixed end is fixed at a center point, or in a position close to the center point, of the bin bottom of a material bin; the screw rack body comprises a supporting frame and a screw sheet fixed to the supporting frame; the supporting frame is provided with holes or gaps through which a material can pass; the first driving device is used to drive the screw rack body to autorotate around the central axis of the screw rack body; and the second driving device is used to drive the screw rack body to rotate around the position where the fixed end is located. By employing the screw conveying principle, radial conveying of the bulk material is accomplished; through the revolution of the whole bulk material bin bottom loosening and cleaning device, the material is pushed into a material outlet at the bottom of the material bin; in addition, the material can pass through the screw rack body to exert the loosening effect; the material remained at the bin bottom of the material bin can be loosened and cleaned effectively; potential safety hazards are eliminated; and the labor productivity is raised.