To investigate the clinical effect of different doses of norepinephrine for preventing hypotension of women during emergency cesarean section under combined spinal-epidural anesthesia. Methods: The clinical data of the women who had undergone emergency cesarean section under combined spinal epidural anesthesia from June 2017 to June 2020 were collected retrospectively. The women were divided in group A (45 women with 10μg/mL norepinephrine injection of 10μg), group B (44 women with 10μg/mL norepinephrine injection of 15μg), and group C (51 women without norepinephrine injection) according to the used situation and the using dosage of norepinephrine. The values of systolic blood pressure (SBP) and heart rate (HR) at different time points, the incidence of adverse reactions during operation, the neonatal Apgar score, and the blood gas analysis results of the women were compared among the three groups. Results: The values of SBP and HR of the women at 5 min, 10 min, 15 min and 20 min after combined spinal-epidural anesthesia in group A, in group B, and in group C had decreased gradually (P＜0.05), but the decreasing degree of which of the women in group A and in group B at 10 min or 15 min after anesthesia was significantly lower than that of the women in group C (P＜0.05). The incidence of hypotension of the women in group A (4.4%) or in group B (4.6%) was significantly lower than that (17.7%) of the women in group C (P＜0.05). There were no significant differences in the incidences of nausea and vomiting, bradycardia, chills, and chest distress of the women among the three groups (P＞0.05). There were no significant differences in the neonatal Apgar scores at 1 min and 5 min after born, and the values of umbilical venous blood PH, PaO2, and PaCO2 of neonates among the three groups (P＞0.05). Conclusion: Norepinephrine used during emergency cesarean section of the women under combined spinal-epidural anesthesia can effectively prevent the occurrence of hypotension, and which has little influence on their neonates. The recommended dasage of 10μg/mL norepinephrine is 10μg.