The widespread use of antibiotics abuse lead to bacterial resistance increased, thus to explore the new method of antibacterial, search for new antimicrobial agents has very important significance. In this paper, solvents of different polarity were used to extract extracts from jujube fruits with different polarity ranges from low polarity to high polarity. By detecting the antimicrobial we screened the effect of the extracts and the synergistic antimicrobial effect of the extracts and antibiotics, the active extracts with antimicrobial and antibiotic sensitization effects. The active extracts were further isolated and purified by column chromatography with activity tracking. (1) Among all the extracts of jujube fruits, only chloroform extract of wild jujube fruits has broadspectrum antibacterial effect and can significantly enhance the sensitivity of Pseudomonas aeruginosa to ampicillin, while other extracts have no corresponding biological activity. (2) Fr.2a component obtained by further refining the chloroform extract of wild jujube fruits, GCMS analysis showed that it contained 49.59% of 1, 3dichloropropanol, 5.49% of 1, 1dichloromethyl ether, 0.96% of hexachloroethane, 7.81% of 1, 1, 2, 3tetrachloro2propylene, 1.33% of lauric acid, 1.34% of myristic acid, 0.87% of palmitoleic acid, 7.37% of palmitic acid, 9.75% of dibutyl phthalate, 2.02% of trans13octadecentenoic acid, 1.88% of oleamide, 3.06% of βamyrin, 0.93% of αacorenol alcohol, 6.20% of lupeol, 1.42% of ursolic aldehyde. (3) The combination of Fr.2a with a variety of antibiotics showed extensive synergistic antimicrobial effects, while Fr.2a in a dosedependent manner promoted the formation of microbial biofilms, reduced microbial motility and significantly inhibited the growth of microorganisms in milk. These studies have laid a foundation for the development of wild jujube medicinal products and natural preservatives.