Abstract: A novel acoustic metamaterial structure, inspired by the shape of butterfly arc, is proposed to address the issue of low-frequency absorption performance in Helmholtz resonators. In this paper, a butterfly-like arc resonance cavity acoustic metamaterial structure is proposed, and a stepped round hole is introduced into the neck tube of the Helmholtz resonator, and the traditional negative Poisson's ratio concave sandwich structure is changed, so that the structure can effectively provide the acoustic impedance required for low-frequency sound absorption for the sound absorber without changing the overall size, so as to reduce the resonance frequency. The structure was numerically simulated using COMSOL 6.1 finite element software and validated through a standing wave tube absorption test experiment, showing a high level of consistency between the experimental and simulated results. The results demonstrate that butterfly-like arc resonance cavity acoustic metamaterial structure can effectively reduce the absorption peak frequency of Helmholtz resonators, achieving excellent sound absorption performance in the frequency range of 650-1050 Hz, with an average sound absorption coefficient greater than 0.9. The structure achieves near-perfect absorption of sound waves. At the resonance absorption peak of 740 Hz, the structure thickness is only 1/15 of the corresponding wavelength, highlighting its deep subwavelength characteristics. Even at a height of 30 mm, the structure still exhibits a wide absorption bandwidth with a bandwidth ratio of 62% (Sound absorption coefficient > 0.5). The sound absorption performance is also influenced by different parameters of the butterfly arc-shaped negative Poisson's ratio unit cell. When the circular arc radius (r) of the arc-shaped cell is 11.8 mm, the number of steps (n) in the step-like circular hole is 4, and the diameter (d_a) and length (l_a) of the step-like circular hole correspond to the specimen size, the Helmholtz resonator exhibits excellent sound absorption performance over a wide low-frequency band.