Maintaining cell membrane homeostasis is crucial for suppressing postharvest browning in Agaricus bisporus (A.bisporus). This study utilized transcriptomics to investigate the effects of 50 kJ m⁻² ultraviolet B (UV-B) irradiation on cellular membrane homeostasis and metabolic pathways in post-harvest A.bisporus. Results found that 50 kJ m−2 UV-B irradiation treatment effectively attenuated cellular deformation and cytoplasmic leakage by suppressing membrane lipid peroxidation and regulating membrane permeability. The activities of polyphenol oxidase (PPO), tyrosinase (TYR), and laccase (LAC) were reduced by 18.66 %, 27.75 %, and 15.27 %, respectively, compared with the control group, accompanied by the downregulation of the corresponding genes expression levels. The differential expressed genes (DEGs) were mainly clustered in the pathways of fatty acid metabolism, phospholipid metabolism, tryptophan metabolism, and glutathione metabolism. These findings demonstrate that UV-B irradiation treatment delays browning through dual regulation of membrane integrity maintenance and browning-related metabolic suppression.