〔Abstract〕 Objective To analyze and study the influence of application time of antibacterial drugs on premature rupture of membranes in preterm parturients. Methods A total of 72 premature parturients with premature fetal membranes admitted to Luoyang Dongfang Hospital from October 2018 to October 2019 were selected and divided into group I, group II and group III according to the application time of antimicrobial drugs. All three groups were 24 example. Groups Ⅰ, Ⅱ and Ⅲ were respectively treated with the antibacterial drug cefazolin sodium within 12 hours, 12-24 hours, and more than 24 hours after fetal membrane rupture, and the medication was continued for 3 days. Compare the clinical efficacy of the three groups. Results The time from admission to delivery in group I was (62.76 ± 4.97) h, the time in group II was (58.04 ± 4.53) h, and the time in group III was (53.41 ± 4.74) h. The time in group I was significantly longer than those in groups II and III. The difference was statistically significant (P < 0.05); The incidence of postpartum hemorrhage, intrauterine infection and puerperal infection in group Ⅰ were significantly lower than those in groups Ⅱ and Ⅲ, and the differences were statistically significant (P < 0.05) The Apgar score for the health status of the newborns in group Ⅰ was (8.27 ± 0.44), the Apgarscore in group Ⅱ was scored (7.80 ± 0.42), and the Apgarscore in group Ⅲ was (7.64 ± 0.40). The score in group Ⅰ were significantly higher than those in groups Ⅱ and Ⅲ , the difference was statistically significant (P < 0.05). Conclusion Early application of antimicrobial therapy after premature rupture of membranes in preterm women has less impact on pregnancy outcome.