The invention discloses a sound absorbing structure and a sound attenuation channel. The sound absorbing structure is formed by multiple sound attenuation units; the sound absorbing unit is formed by a base layer and multiple sound attenuation wedge structures; each sound attenuation wedge structure is formed by two parts of a base part and a tip end; the cross section area of the tip end is smaller than the cross section area of the base part; all base parts are fixed on the base layer at intervals; the tip ends are hung and stretch towards the direction far away from the base layer; one surface of the base layer, which is not fixedly provided with the sound attenuation wedge structures, is hung on the internal wall of an air channel, and is away from the air channel by a 0-0.2 m air gap, thus, by utilizing the gradual change of impedance, from the tip ends to the base parts of the sound attenuation wedge structures, the sound attenuation is gradually transited to the impedance of the base layer material from the impedance of air, thereby realizing good impedance matching; and moreover, the incident sound from various directions and with wide frequency band can be absorbed efficiently, thereby reaching efficient noise reduction effect.