Dust filtering device

The utility model relates to a dust filtering device which comprises an upper short pipe and a lower short pipe, supporting plates are arranged on the front side and the rear side between the two short pipes respectively, a first rotating shaft is rotationally connected between the two supporting plates, a front circular plate and a rear circular plate are fixed to the first rotating shaft, and a first annular plate is fixed between the two circular plates. Four through holes are evenly formed in the outer edge face of the first annular plate in the circumferential direction, a filter screen is fixed to each through hole, four partition plates are evenly distributed on the first rotating shaft in the circumferential direction, every two opposite cavities are communicated with each other, a second annular plate is arranged on the outer side of the first annular plate and rotates around the axis all the time, and bristles are arranged on the inner edge face of the second annular plate. The ends of the bristles