The invention discloses a dust-free vibrating screen comprising a screening box body. A downward-obliquing first screen body is fixed on the upper portion of the inner side wall of the screening box body, and a gap is reserved between the lower end of the first screen body and the screening box body; a downward-obliquing second screen body is fixed on the middle of the inner side wall, far from the first screen body, of the screening box body; a downward-obliquing third screen body is fixed on the middle of the inner side wall, far from the second screen body, of the screening box body; the lower end of the third screen body is connected with the inner wall of the screening box body and penetrates through the side wall of the screening box body; the top of a feeding pipeline is connected with an obliquely-arranged oblique pipeline; the upper end of the oblique pipeline is connected with a feeding hopper; a dust-proof cover is hinged to an opening of the top of the feeding hopper; a telescopic mechanism is hinged to the bottom of the dust-proof cover; and the lower end of the telescopic mechanism is hinged on the inner wall of the feeding hopper. The dust-free vibrating screen is novel in structure, ingenious in design, reasonable in structure and suitable for being popularized.