Abstract: Honeycomb micro-perforation structure has been widely used in the field of sound absorption and noise reduction, and so it must have good wideband sound absorption and noise reduction performances. In order to make up for the deficiency of low-frequency sound absorption performance of the single-layer micro-perforated plate structure and realize the wideband noise reduction in the middle and low frequency range, a support structure of Helmholtz resonator (HR) array is introduced on the basis of the traditional single-layer micro-perforated plate structure unit and the particle swarm optimization (PSO) algorithm is used to optimize the sound absorption performance of the designed structure in this paper. By numerical analysis, finite element simulation and experimental test, the wideband sound absorption characteristics of the honeycomb micro-perforated sound absorber with built-in HR array are verified. The results show that the optimized design of the honeycomb micro-perforated sound absorber with built-in HR array has good sound absorption performance in the middle and low frequency range, especially at 200-400 Hz, and the bandwidth ratio with sound absorption efficiency exceeding 65% reaches more than 70% at 0-1000 Hz.