Abstract: Objective: The deep eutectic solvent was used to extract the amentoflavone (AME) of Selaginella uncinata and the extraction process parameters were optimized. Method: Three deep eutectic solvents were synthesized and screened, and then the structure of the deep eutectic solvent with the best extraction effect was characterized. The effect of extraction time, extraction temperature, extraction power, and liquid-solid ratio on the extraction effect of amentoflavone from Selaginella uncinata were investigated. The response surface design technology was further used to optimize the extraction conditions, and compared with traditional extraction methods (dipping method, percolation method, ultrasonic method). Results: The suitable deep eutectic solvent for extracting AME was selected as choline chloride: 4-terpineol. The best extraction conditions were: Ultrasonic power of 280 W, liquid-to-solid ratio of 16:1 mL/g, extraction temperature of 48 ℃, extraction time of 24 min, and AME maximum extraction of (0.941±0.07) mg/g. Compared with the ultrasonic method, cold soaking method, and hot soaking method, the content of AME extracted by eutectic solvent was increased nearly 5 times, and the extraction time was shortened by 1/10 (P<0.05). Conclusion: The deep eutectic solvent extraction method was an efficient, fast and simple extraction method, which can provide some references for the extraction and research of the effective components of traditional Chinese medicine.