Abstract: Objective To investigate the effect of three doses of bupivacaine in caesarean section under combined spinal-epidural anesthesia for parturients with normal body mass. Methods From June 2017 to July2018, 150 parturients undergoing cesarean section in Yan'an Hospital affiliated to Kunming Medical University were divided into group A, B and C (n = 50 cases) . Combined spinal-epidural anesthesia was performed in L3-4 space, 0.75% bupivacaine injection 10 mg, 11.5 mg and 12.5 mg were respectively injected into the subarachnoid, and the parturient were assisted to take a horizontal position after placing epidural tube 4 cm on the head side. The anesthesia sensation blocking plane was measured every 2 min. HR, Sp O2 and BP were recorded, and the occurrence of adverse reactions such as hypotension, bradycardia, tachycardia, nausea, vomiting and chest distress was closely observed and handled in time. Results There was no significant difference in age, height, weight and BMI (kg/m2) between the three groups (P > 0.05) . The operation time in group A was significantly longer than that in groups B and C (P < 0.05) , and the anesthesia onset time, analgesic effect and muscle relaxation effect in groups B and C were better than those in group A (P < 0.05) . MBP in group C was significantly lower than that in group A and B after the fetus was taken out and at the end of the operation, while HR in 5 minutes after injection was significantly higher than that in group A and B ( P < 0.05) . There was no significant difference in hypotension, nausea and vomiting and the use of antihypertensive drugs in the three groups.Conclusion Under the condition that the drug concentration, injection speed and puncture site selection are unchanged, according to the method of 0.75 % bupivacaine 2 m L plus cerebrospinal fluid 1 ml, 11.5 mg (2.3 m L) of bupivacaine for combined spinal-epidural anesthesia for parturients with normal body mass may be the most appropriate and safe dose in clinical anesthesia.