Objective: To explore the value of color doppler ultrasonography monitoring uterine scar on the evaluation of risk of re-pregnancy risk. Methods: The 138 case patients with uterine scar pregnancy again as the research object that who were treated in our hospital from January 2016 to April 2017, all patients were screened with color doppler ultrasound and to grade the scar, to compared the different scar levels of patients that which the blood loss during delivery, oxytocin dosage during delivery, incidence of uterine rupture, serious infection rates, thickness of the anterior wall of the uterus and delivery way. Results: The 138 case patients of uterine scar for grade I stage 82 cases (59.42%), II stage 30 cases (21.74%), III stage 21 cases (15.22%), IV stage 5 cases (3.62%), uterine scar defect rate was 40.58% (56/82); The thickness of the anterior wall of the uterus of I stage group > II stage group > III stage group > IIV stage group, were statistically significant (P<0.05); During delivery of blood loss, oxytocin dosage and uterine rupture, severe infection, uterine bleeding after childbirth of I stage group < II stage group < III stage group < IIV stage group, compare the difference between groups was statistically significant (P<0.05); The vaginal delivery rate of I stage group > II stage group > III stage group and IIV stage group, were statistical significance (P<0.05). Conclusion: Ultrasonic testing of uterine scar defects can predict bleeding, uterine rupture and severe infection in childbirth, etc., is helpful to assessment of the risks of scar uterus pregnancy again, provide the basis for scientific choose childbirth way.