Abstract: The micro-perforation is successfully made on the 1mm 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 mi-cro-perforation is shifted to high frequency region and the sound absorption coefficient is reduced. In this case, there is no synergetic sound absorption of micro-perforation. The electro-acoustical equivalent circuit model might not be applied to predicting and designing the sound absorption characteristics of this absorber. Based on the acoustic theory such as Helmholtz sound absorption method, a method of calculating the sound absorption characteristics of micro-perforation under small local conditions is established, which could solve the structural design problem of sandwich micro-perforated absorber with small back cavities, and prepare for the next step to optimize the structure of such absorbers.