To explore the application value of the high-frequency ultrasound for evaluating the prenatal situation of pregnant women with cesarean section history who wanted vaginal delivery. Methods: 80 pregnant women with cesarean section history who had delivered in hospital from February 2019 to November 2022 were selected retrospectively. According to the results of the high-frequency ultrasound examination, these women were divided into group A(women with the grade Ⅰ scar of uterus), group B(women with the grade Ⅱ scar of uterus) and group C(women with the grade Ⅲ scar of uterus). The delivery situation, the thickness and morphology of the lower segment of the uterus muscle layer and the resistance index of trophoblastic artery evaluated by ultrasound, the labor process related indicators, and the neonatal Apgar score of the women were compared among the three groups. Results: The rate of the cesarean section the women during delivery in group A was the lowest, and the vaginal delivery rate was the highest. The cesarean section rate of the women in group C was the highest, and there was no any woman with vaginal delivery in group C. The thickness of the lower uterine segment muscle layer of the women in group A was the thickest, but which of the women in group C was the thinnest(all P<0.05). There were no significant differences in the trophoblastic artery resistance index of the women, and the neonatal weight and Apgar score among the three groups(all P>0.05). The labor duration, the amount of bleeding and the dosages of oxytocin used of the women in group A were the lowest, while which of the women in group C were the highest(all P<0.05). Among 80 pregnant women with cesarean section history, there were 61(76.3%) cases with successful vaginal delivery, 1(1.6%) case with uterine rupture, and 19(23.8%) had been cesarean section again. There was no any maternal or perinatal death. Conclusion: The high frequency ultrasound can accurately identify the scar healing status of the women by monitoring the thickness and shape of their lower segment of the uterine muscle layer, and which has high guiding value for the selection of delivery mode of the pregnant women with scar uterus caused by cesarean section, can promote the rational and safe selection of the delivery methods of the women, and so as to improve the rate of the vaginal delivery of these women.