Draught fan inlet and outlet silencer

The utility model relates to the field of noise processing, and provides a draught fan inlet and outlet silencer. The draught fan inlet and outlet silencer comprises a shell. The wall of the shell is internally provided with a built-in sound insulating gasket, a double-layer sound absorption micro-hole plate is arranged on the periphery of the interior of the shell, and a plurality of isolating rings are arranged between the outer layer sound absorption micro-hole plate and the shell to isolate cavities with different volumes, the size of the cavities gradually becomes smaller from an inlet to an outlet, and a conical sound absorption body is arranged in the middle of the shell and is composed of double-layer sound absorption micro-hole plates. According to the draught fan inlet and outlet silencer, the characters of sound are fully utilized, the silencing function is very stable, and the service life of the draught fan inlet and outlet silencer is long.