<p>In this study, ultrasonic-assisted extraction method was used to extract polyphenols from pecan 'Shaoxing' green husk. The optimization of extraction technology involved both single-factor and response surface methodology, while the purification technology was determined to refine the crude polyphenol extract. Assessment of radical scavenging activity of pecan 'Shaoxing' green husk polyphenols on 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radical (<b>•</b>OH), and superoxide anion (O_<b>2</b>^{<b>•−</b>}) was conducted with L-ascorbic acid (Vc) as the control. Results showed that optimal extraction conditions, including ethanol solvent, material-liquid ratio of 1:15, 58% ethanol volume fraction, 60 min ultrasonic time, 160 W ultrasonic power, and 57 ℃ ultrasonic temperature, yielded a polyphenol content of 218.62 mg/g. Macroporous resin D-101 was selected for polyphenol purification with optimized parameters: 2 mg/mL loading concentration, pH = 4, 2 mL/min loading flow rate, elution with 70% ethanol volume fraction, and 3 mL/min elution flow rate. The purity of polyphenols increased from 31.45 to 69.34%. At the pecan 'Shaoxing' green husk polyphenol concentration of 0.9 mg/mL, DPPH, ABTS, O_<b>2</b>^{<b>•−</b>}_<b>,</b> and <b>•</b>OH radical scavenging activity were measured at 95.36, 99.4, 50.92, and 51.89%, respectively, indicating significant antioxidant activity. LC–MS analysis detected 24 polyphenol components in pecan 'Shaoxing' green husk, with relatively higher rutin and proanthocyanidin B2 contents compared to other components.</p> Graphical Abstract <p></p>