Individual fruiting bodies of Pleurotus eryngii were treated with LED irradiation of different wavelengths and flux densities of light at low temperatures (12~15 ℃ ) to investigate the effect of irradiation with blue-white light derived from light emitting diodes (LED) on the shelf-life of P. eryngii. Treatment without LED irradiation, or with the lighting conditions typical of supermarket shelves [28 μmol/(m2•s)], or with supermarket lighting [4.3 μmol/(m2•s)], were used as controls 1, 2, and 3, respectively. Analyses of the appearance of P. eryngii exposed to irradiation with LED blue-white composite light (blue light: green light: red light=8.4:2.3:1.3) demonstrated that treatment with LED light was suitable for storing P. eryngii. Thereafter, the effect of LED blue-white composite light on postharvest browning of P. eryngii was investigated by selecting the light quality ratio above as the treatment group. The control groups were set as described above, and a blue light [8 μmol/(m2•s)] positive control group was added. Compared with the control groups, exposure to LED blue-white composite light increased the activity of antioxidant enzymes (e.g., superoxide dismutase and catalase) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability of P. eryngii. Furthermore, the treatment reduced the production rate of superoxide anion radicals and hydrogen peroxide content, thereby protecting P. eryngii cells from damage caused by the accumulation of reactive oxygen species. It also inhibited the increase in relative conductivity and malondialdehyde content. Additionally, composite LED irradiation reduced the activity of polyphenol oxidase, maintained a high total phenol content, and hence delayed the browning of P. eryngii. During days 2~8, the degree of browning of the group irradiated with blue–white composite light was 2.24~5.00, 1.59~3.23, and 0.90~1.77 times lower than those of controls 1, 2, and 3, respectively. Principal component analysis and correlation analysis revealed that blue-white composite LED irradiation (blue: green: red light=8.4:2.3:1.3) effectively delayed postharvest browning and preserved the overall quality of P. eryngii. These findings provide theoretical and technical foundation for the application of LED irradiation in the postharvest preservation of edible fungi.