The utility model relates to an air quantity regulating valve for a dust-cleaning system. The utility model has the technical scheme that a fixed perforated plate [3] and a movable perforated plate [2] which are mutually and closely contacted are arranged on an inlet of a valve body [1]; the fixed perforated plate [3] and the valve body [1] are fixedly connected; a flow guiding plate [4] is welded on the middle part of a hole bridge on one side of the fixed porous plate [3]; the outer side of the valve body [1] is provided with a regulating supporter [9], and a regulating screw [6] is movably matched and arranged in the regulating supporter [9]; one end of the regulating screw [6] is connected with a regulating handle [8], and a nut [5] on the other end of the regulating screw [6] is fixedly connected with the movable porous plate [2]. The shape, the size, the number and the layout of the fixed perforated plate [3] and the movable perforated plate [2] are same. The shapes of the holes of the fixed perforated plate [3] and the movable perforated plate [2] are rectangular or circular. The utility model has the characteristics of simple structure, uniform air flow distribution, favorable abrasive resistance and low cost. The service life of the utility model is three to five times of a common air quantity regulating valve.