Noise reducer of dust collector

The invention discloses a noise reducer of a dust collector, which comprises a reflecting cover plate, the reflection cover plate comprises a large horn mouth part, a small horn mouth part located in the first horn mouth part, a reflection face part located in the small horn mouth part, a first supporting structure connected between the large horn mouth part and the small horn mouth part in a supporting mode, and a second supporting structure connected between the small horn mouth part and the reflection panel in a supporting mode. Wherein the large horn mouth part and the small horn mouth part extend in the same direction with the large mouth end facing forwards and the small mouth end facing backwards, a first air inlet channel is formed among the large horn mouth part, the small horn mouth part and the first supporting structure, and a second air inlet channel is formed among the small horn mouth part, the reflecting surface part and the second supporting structure. By means of the double-horn-mouth struct