Abstract: Under the constraint of constant structure sizes of Helmholtz resonator composite structure, a method that can effectively improve the acoustic absorption performance of the structure is studied. First, based on the acoustoelectric analogy, a single cavity Helmholtz resonator is designed. Second, the single cavity is divided unevenly into multiple cavities with different depths to form a composite structure composed of multiple Helmholtz resonators, and a mathematical model is established to calculate its sound absorption coefficient. Then, porous materials are added to the cavities of the composite structure, and the influence of the material thickness on the sound absorption coefficient is analyzed. Finally, in order to obtain good acoustic absorption performances, micro-perforated plates are utilized to replace porous materials in the composite structure. The results show that, the acoustic absorption performance can be significantly improved by non-uniform division of a single-cavity, however, with the increase of the number of cavity, the low cutoff frequency tends to the high frequency; the effect of porous materials on the acoustic absorption performance is very limited; the arrangement of micro-perforated plates in the cavities of the composite structure can greatly broaden the effective sound absorption bandwidth and increase the overall sound absorption coefficient, and with the increase of the number of parallel chambers, the improvement effect of acoustic absorption performance is more obvious, and the sound absorption coefficient curve is smoother.