Objective To optimize the purification process of peanut skin polyphenols (PSPs), improve purification efficiency, and investigate their in vitro hypoglycemic activity.Methods Three types of PSPs (red, white, and purple) were extracted by ultrasound-assisted ethanol extraction. Seven macroporous resins were used for static adsorption and desorption of PSPs, and the resin with the best performance was selected for single-factor experiments. The components of the purified PSPs were analyzed by UPLC-ESI-QTOF-MS/MS. Using acarbose as a positive control, the inhibitory activity and inhibition types of PSPs against α-amylase and α-glucosidase were investigated.Results Purple peanut skins exhibited the highest contents of total phenols, total flavonoids, and anthocyanins. NKA-9 resin showed the best adsorption and desorption performance for PSPs. The optimized purification conditions were as follows: PSP concentration of 2.5 mg/mL, solution pH of 5, eluent concentration of 70%, sample loading flow rate of 2 BV/h, and elution flow rate of 1 BV/h. Under these conditions, the purity of PSPs reached 77.42%, representing a 2.27-fold increase. A total of 19 phenolic compounds, including procyanidins B₁, B₂, B₄, gallic acid, and kaempferol, were identified in the purified PSPs. The half-inhibitory concentrations (IC₅₀) of PSPs against α-amylase and α-glucosidase were 96.33 and 7.01 μg/mL, respectively, and both exhibited mixed-type inhibition.Conclusion Purified PSPs exhibit excellent in vitro hypoglycemic activity and have potential for development and utilization as functional ingredients in hypoglycemic foods.