Abstract: To inhibit microbial spoilage in fresh and wet vermicelli and explore green and efficient preservatives, this study systematically investigated the antibacterial mechanism of hydrogen peroxide (H₂O₂), a green preservative, against the predominant spoilage bacteria in fresh and wet vermicelli. Firstly, the predominant spoilage bacteria in fresh and wet vermicelli were identified as Bacillus aryabhattai through high-throughput sequencing. Then, the influence of H₂O₂ on the inhibition zone diameter (IZD), the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC) and the growth curve of B. aryabhattai were analyzed through antibacterial activity assays. Simultaneously, the mechanism of antibacterial action experiments was conducted to observe the effects of H₂O₂ on the disruption of cell membrane and cell wall of B. aryabhattai, as well as the leakage of intracellular functional components. The results showed that increasing the concentration of H₂O₂ from 250 μg/mL to 1000 μg/mL resulted in an 8 mm increased IZD. Additionally, MIC and MBC of H₂O₂ were both 250 μg/mL. The growth curve analysis revealed that bacterial growth was completely inhibited within 24 hours when the concentration of H₂O₂ was higher than 250 μg/mL. The mechanism of antibacterial action experiments indicated that increasing concentrations of H₂O₂ significantly raised the concentrations of nucleic acids and proteins in the supernatant of the bacterial liquid (P<0.05), while also disrupting the cell wall and membrane structure of B. aryabhattai, leading to the leakage of alkaline phosphatase (AKP) and β-galactosidase (β-GAL) outside the cells, and it exhibited a concentration-dependent relationship with H₂O₂. Therefore, H₂O₂ at 250 μg/mL effectively inhibited the activity of B. aryabhattai in fresh and wet vermicelli. This study provides a theoretical basis and production guidance for extending the shelf life and increasing the market value of fresh and wet vermicelli.