Walnut green husk obtained by peeling green walnuts was used as raw material. A two-phase salt precipitation extraction method was employed to extract its active ingredients, sequentially using petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EA), and n-butanol (n-BuOH) as solvents to obtain fraction 1 to fraction 4 through extraction and separation. Ultra high performance liquid chromatography quadrupole electrostatic field orbital trap mass spectrometer (UHPLC-Q-Exactive) was utilized to identify the compound compositions of the fractions. Antibacterial experiments against E. coli, S. aureus, and B. subtilis were conducted to investigate the influence of browning and non-browning of walnut green husk on the fractions and antibacterial activity of the extracts. Network pharmacology and molecular docking methods were employed to analyze the correlation between extract compositions and antibacterial activities, exploring the main antibacterial components and their mechanisms in walnut green husks. Results showed that the antibacterial activities of fraction 2 (DCM extract) and fraction 3 (EA extract) were insignificantly affected by browning of walnut green husk (P > 0.05), whereas the antibacterial activities of fraction 1 (PE extract) and fraction 4 (n-BuOH extract) were significantly affected by browning of walnut green husk (P < 0.05). Compared to non-browning walnut green husk, the antibacterial activities of fraction 1 decreased by 100%, 36.58%, and 39.53% against the tested bacteria, while those of fraction 4 increased by 128.49%, 53.32%, and 78.50%, respectively. The reduced antibacterial activity after browning of walnut green husk was correlated with decreased content of quinone compounds (2-hydroxy-1,4-benzoquinone, 2-hydroxy-1,4-naphthoquinone,1,4-naphthoquinone and hydroquinone), flavonoid compounds (quercetin pentaacetate, naringenin and isoquercetin), and steroid compounds (prsapogemin A and 3,5-dihydroxycholestan-6-one), whereas enhanced antibacterial activity was associated with increased content of quinone derivatives (tetrahydroxyquinone, menaquinone and compound d ) and alkaloids (minovincinine). Fraction 1 and fraction 4 mainly exert antibacterial effects through negative regulation of apoptosis processes, binding to the same proteins, and enzyme binding pathways.