OBJECTIVE To optimize the extraction process of organic acids from Angelica sinensis using deep eutectic solvents （DESs）， and conduct characterization， antioxidant activity evaluation， and extraction mechanism analysis. METHODS The conductor-like screening model for realistic solvation with segment activity coefficients （COSMO-SAC） was employed to screen the types of DESs. With total organic acid content as the response value， single-factor experiments and Box-Behnken response-surface methodology were used to optimize the extraction conditions. Using A. sinensis decoction pieces and/or A. sinensis methanol extract as references， scanning electron microscope and Fourier transform infrared spectrometer （FTIR） were applied to characterize the products. Additionally， the 1，1-diphenyl-2-picrylhydrazyl （DPPH） and 2，2′-azino-bis（3-ethylbenzothiazoline-6- sulfonic acid） （ABTS） free radical scavenging capacities were determined. Density functional theory （DFT） was used to analyze the extraction mechanism of ferulic acid and chlorogenic acid by the DESs. RESULTS & CONCLUSIONS The optimal DESs was choline chloride-propanediol. The optimal extraction conditions for organic acids from A. sinensis were as follows： choline chloride- propanediol molar ratio of 1∶1， DESs water content of 70%， solid-liquid ratio of 1∶10， heating temperature of 57 ℃， and heating and stirring time of 8 min. In three validation experiments， the total organic acid content was 2.92 mg/g， yielding a relative error of 0.34% compared to the predicted value （2.91 mg/g）. Compared with A. sinensis decoction pieces and methanol extracts， the agglomerated structure of the DESs extract powder almost disappeared， showing the presence of lamellar structures similar to those of the intestinal wall. Compared with the methanol extract， the DES extract exhibited higher FTIR characteristic peak intensity and peak area integration， as well as stronger scavenging capacities against DPPH and ABTS free radicals. The extraction of organic acids from A. sinensis by DESs is the result of the combined effects of polarity matching， hydrogen bonding， and structural adaptation.