The self-cleaning cage drum screening machine uses a gearbox-type deceleration system to reasonably rotate the center separation cylinder of the equipment. The center separation cylinder is a screen composed of several annular flat steel rings. The center separation cylinder is installed in an inclined state with respect to the ground plane. During operation, the material enters the cylinder net from the upper end of the center separation cylinder. During the rotation of the separation cylinder, the fine material is separated from the top to the bottom through the screen interval composed of annular flat steel, and the coarse material is discharged from the lower end of the separation cylinder into the crusher. The equipment is equipped with a plate-type automatic screening mechanism. During the separation process, the screening mechanism continuously “combs” the screen body through the relative movement between the screening mechanism and the screen body, so that the screen body is always kept clean during the entire working process, and the screening efficiency will not be affected by the blockage of the screen holes., ,