Abstract: In order to study the extraction process and antioxidative activity of polyphenols from Bangia fusco-purpurea, solvent extraction was used to extract polyphenols. The polyphenol content in the extract was used as an index. The extraction time, extraction temperature, ethanol volume fraction, and liquid-liquid ratio were single factors. Further, the optimal extraction process was determined by orthogonal experiment optimization. The clearance rate of DPPH and ABTS free radical were used as indicators to evaluate the antioxidative activity of B. fusco-purpurea polyphenols. The results showed that the optimum extraction conditions were as follows: Extraction temperature 70 ℃, extraction time 70 min, volume fraction of ethanol 60%, ratio of material to liquid 1:10 g/mL.Under these conditions, the extraction amount of B. fusco-purpurea polyphenols was (9.67 ± 0.14) mg/g. Antioxidant activity evaluation showed that B. fusco-purpurea polyphenols had a certain scavenging ability to DPPH• and ABTS⁺•, with IC₅₀ values of 0.313, 0.445 mg/mL. The results showed that the orthogonal optimization process for extracting B. fusco-purpurea polyphenol was simple and feasible, the polyphenols had certain antioxidant capacity. B. fusco-purpurea polyphenol has the potential to be developed as a natural antioxidant and has a good application prospect.