Backgroud: The clinical efficacy and safety of cervical pessary versus cervical cerclage in preventing spontaneous preterm birth remain uncertain. Objectives: To systematically review the clinical efficacy of cervical pessary versus transvaginal cervical cerclage in preventing spontaneous preterm birth caused by cervical shortening. Search Strategy: The Cochrane Library, PubMed, EMbase, WanFang Data, CNKI, VIP Data and CBM Data were electronically searched. Selection Criteria: Randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs, including cohort studies) comparing cervical pessary and transvaginal cervical cerclage in preventing spontaneous preterm birth from the inception of the database to August 2020. Main Results: A total of 9 studies (2 RCTs and 7 non-RCTs) were included, involving 1174 patients with a short cervix in the second trimester (cervical length <25mm), 693 in the cervical pessary group and 481 in the cervical cerclage group. The results of meta-analysis showed that the incidence of preterm premature rupture of the membranes (PPROM) in the cervical pessary group was significantly lower than that in the cervical cerclage group (RR=0.48, 95% CI: 0.35 to 0.67, P<0.00001), and the premature birth rate before 34 weeks in the cervical pessary group was also significantly lower than that in the cervical cerclage group (RR=0.68, 95%CI: 0.51 to 0.89, P<0.006). Conclusion: Compared with transvaginal cervical cerclage, use of a cervical pessary may decrease the risks of PPROM and premature birth before 34 weeks. Given its advantages of easy-to-use and minimal damage, cervical pessary may become a useful preventive intervention that deserves widespread clinical application.