The micro-perforation is successfully made on the 1 mm thick carbon fiber reinforced resin sheet. Based on this, a sandwich micro-perforated absorber is prepared. The influence of local condition on the sound absorption of this absorber is studied by the impedance tube test method. The results show that the addition of small back cavities has a strong inhibitory effect on the sound absorption of micro-perforation, and the sound absorption frequency of micro-perforation is shifted to high frequency region an...