Portulaca oleracea is widely distributed around the world and has a long history of dual use in the fields of medicine and food. Its chemical constituents include flavonoids, polyphenols, terpenoids, sterols, coumarins, alkaloids, polysaccharides and organic acids, which make it have excellent antibacterial and antioxidant effects. More and more research has reported the antibacterial activity of Portulaca oleracea, which is significantly different on different bacteria, but a systematic review is lacking. In this paper, we summarize recent progress in research on the chemical composition, antimicrobial effect and mechanism of Portulaca oleracea in order to provide as a reference for the bioefficacy research, clinical application and product development of Portulaca oleracea.