The invention relates to a wideband sound absorption unit plate and belongs to the field of noise reduction by sound absorption. The sound absorption unit plate mainly comprises a sound insulation plate cavity, a resonant thin plate or a resonant thin film, a perforated or micro-perforated plate, an aluminum fiber plate and a shell. The sound absorption unit plate has a layered structure and comprises the aluminum fiber plate, the perforated or micro-perforated plate, the resonant thin plate or the resonant thin film and the sound insulation plate cavity in sequence from the front face to the rear face, and the shell is packaged around the other four faces, except for the front face and the rear face, of the unit plate. The sound absorption unit plate is wide in sound absorption frequency band, and especially the sound absorption effect at the low frequency band is greatly improved. The wideband sound absorption unit plate is simple in structure, low in weight, easy to machine and manufacture, wide in application range and capable of being applied to noise reduction by sound elimination in places of indoor walls, outdoor sound barriers, station platforms, railway lines and the like.