Renewable lignin, the richest natural source of aromatics, can be biorefined to produce high-value products to reduce fossil energy consumption. Deep eutectic solvents (DES) have been widely utilized in lignocellulosic biorefineries due to their unique ability to extract lignin in recent years. However, a comprehensive review of the main factors affecting lignin extraction by DES is currently lacking, and their lignin extraction mechanisms have not been systematically summarized. This work reviewed the research progress of the lignin extraction process by DES and the effects of the main parameters, aiming to fill this gap in the literature. The influence of the changes in the composition of DES on the lignin extraction mechanism was highlighted. In addition, this review discussed the coupling effect between various assisted processes and DES for facilitating lignin extraction purpose and the recycling/recovery potential of the spent DES liquid. Finally, the prospects of various challenges and opportunities in the DES lignin extraction field were visualized.