Objective: To ascertain extract with relative molecular weight cutoff ≤1 kDa as the final product

then optimize extracting combination of herbs in Banxia Baizhu Tianma Tang with semi-bionic enzyme method. Method: Herbs combination was divided into 15 groups

taking yields of gastrodine

glycyrrhetinic acid

total flavonoids

extract and total area of extract HPLC as indexes

extracting combination of herbs in Banxia Baizhu Tianma Tang with semi-bionic enzyme method was optimized by comprehensive scoring. Result: The best combination of six herbs was as following:mixing extraction of Pinelliae Rhizoma

Gastrodia Rhizoma and Atractylodis Macrocephalae Rhizoma

mixing extraction of Poria

Citri Exocarpium Rubrum and Glycyrrhizae Radix et Rhizoma.Yields of gastrodine

glycyrrhetinic acid

total flavonoids

extract and total area of extract HPLC were 1.552 8 mg·g-1

189.864 2 μg·g-1

6.767 4 mg·g-1

0.238 1 g·g-1

7 566.3. Conclusion: This optimized herbs combination is rational and feasible for providing a reference for extraction process of Banxia Baizhu Tianma Tang.