To estimate clinical effects of emergency cervical cerclage in twin pregnancies with cervical dilation ≥1.0 cm in mid-trimester of gestation and to identify risk factors after cerclage. This retrospective cohort study included 99 twin pregnancies with cervical dilation ≥1cm in the mid-trimester of gestation at three institutions, from December 2015 through December 2021. The cases were treated with emergency cervical cerclage (52 cases) or expectant management (47 cases). Compare the pregnancy and neonatal outcomes of the two groups. Multiple logistic regression analysis was used to determine the independent risk factors associated with cerclage. Cerclage placement was associated with significantly longer gestation age and prolongation of the gestational latency (p < .05). In the cases, compared to expectant treatments, spontaneous preterm birth (sPTB) at <26, <28, <30, <32 weeks was significantly less frequent (p < .05). Pre-operation WBC > 11.55 × 109/L, CRP > 10.1 and cervical dilation >3.5 cm were found to be independent risk factors for delivery 28 weeks after cerclage. Cervical cerclage in twin pregnancies with cervical dilation ≥1.0 cm in mid-trimester of gestation may prolong pregnancy and gestation age, and improve pregnancy and neonatal outcomes compared with expectant management. The strongest predictor of sPTB before 28 weeks after ECC were pre-operation WBC >11.55 × 109/L, CRP > 10.1 and cervical dilation >3.5 cm.