Based on Sonchus oleraceus L of shaanxi yulin as raw material, the study mainly involved the following aspects:extraction process was optimized with response surface method, separation and purification was conducted with macroporous resin, the chemical composition of the extract was analyzed with HPLC and the antioxidant activity and antibacterial activity & mechanism was explored in the study. The study had very important practical significance for development of natural antibacterial and antioxidant agent...