Objective To explore the safety and efficiency of cervical expansion balloon in promoting cervical ripening of cicatrical uter women with full-term pregnancy attempting vaginal delivery. Methods Fifty cases of pregnant women at the third trimester with cicatrical uter admitted to Nanshan District Maternal and Child Health Care Hospital of Shenzhen from July 2015 to March 2016 were retrospectively and randomly collected as the observation group. Another 50 pregnant women at the third trimester with normal uter admitted to the same hospital in the same period were retrospectively and randomly collected as the control group. All the cases had indications for labor induction, and had intention and conditions of vaginal delivery. Cervical expansion balloons were used in the two groups to promote cervical ripening. The effective rate of promoting cervical ripening, the outcomes of delivery and the incidences of adverse outcomes were compared between the two groups. Results The differences in effective rate of promoting cervical ripening and success rate of induced labor of cervical ripening of pregnant women between the observation group (66%, 76%) and the control group (76%, 84%) were not statistically significant (P>0.05). There were no significant differences in the time of birth process, amout of postpartum bleeding, birth immediate Apgar score, neonatal birth weight, and vaginal delivery rate, and the incidences of acute chorioamnionitis and cervical laceration of pregnant women between the two groups (P>0.05). Incomplete uterine rupture occurred in one case in the observation group, while none in the control group; neonatal mild asphyxia occurred in one case in the control group, while none in the observation group; the differences were not statistically significant (P>0.05). No postpartum hemorrhage occurred in the two groups. Conclusions Under the premise of strictly following the indications, cervical expansion balloon can be used in promoting cervical ripening at the third trimester of pregnant women with cicatrical uter attempting vaginal delivery, improve the success of attempting vaginal delivery, reduce the occurrence of reduplicated cesarean section, and not increase the incidence of maternal and fetal adverse outcomes.