Traditional organic solvents extracting the artemisinin suffered from large solvent consumption, long recovery time, and high energy consumption. To solve these problems, a dual-circulation CO2?switchable solvent system based on fatty acid was proposed. The extraction of artemisinin by fatty acids was the "outer cycle", and the CO2?controllable polyether amine was the "inner cycle". This dual-circulation system realized the efficient extraction of artemisinin and facile solvent recovery. The orthogonal experiments showed the optimal extraction conditions were as follows: the liquid-solid ratio of 20 mL/g, the ultrasonication time of 1 h, the extraction temperature of 50 ℃, and the extraction time of 2.5 h. Under this condition, the artemisinin amount extracted by n-heptanoic acid was 4.85 mg/g. After separation by polyether amine aqueous solution, the artemisinin amount was 4.37 mg/g. The cycling experiments demonstrated that the extraction amount of artemisinin in the fourth cycle was 78% of that extracted by the fresh solvent. The investigation of the extraction mechanism indicated that the Van der Waals forces and hydrogen bonding were the main molecular interactions in the extraction. The proposed dual-circulation CO2?switchable solvent system based on fatty acids provides a green and sustainable method for artemisinin extraction, which has a broad application prospect.