The invention relates to a roller screen, in particular to a screen self-cleaning device, and belongs to the technical field of pre-mixing mortar equipment in the construction industry. The screen self-cleaning device comprises steel wire cylinder brushes and a roller screen. A suspension beam is fixed over the roller screen. The multiple steel wire cylinder brushes are arranged at the lower end of the suspension beam and are closely attached to the surface of the roller screen. The two ends of each steel wire cylinder brush are connected with bearing connecting plates through bearings. The bearing connecting plates at the two ends of each steel wire cylinder brush are connected with hanging brackets through rotary pins, and the hanging brackets are fixed to the lower surface of the suspension beam. A balance weight assembly is welded to each bearing connecting plate, and each balance weight assembly and the corresponding steel wire cylinder brush are symmetrically arranged on the left side and the right side of the suspension beam. According to the screen self-cleaning device, by means of contact friction force, the steel wire cylinder brushes and a screen face screen body of the roller screen achieve engagement and opposite rolling, the steel wire cylinder brushes are driven by rotation of the roller screen to achieve autoroatation, steel wires of the steel wire cylinder brushes on the whole circumference are cut into the screen body of the roller screen, and automatic and continuous cleaning is achieved.