Objective To explore the best timing of pushing with abdominal muscles during the second stage of epidural anesthesia assisted labor in primiparas. Methods Totally, 172 pregnant women going through first-time vaginal delivery under epidural anesthesia were sequentially assigned into 2 groups.The control group (n=86) were asked to push with the abdominal muscles after the cervix was fully opened, while the intervention group (n=86) were asked to push with the abdominal muscles when the fetus pre-sentation descended 3 cm.The length of second stage of labor, the length of pushing with the abdominal muscles, the degree of perineal laceration, the rate of episiotomy, the level of postpartum fatigue, and birth outcomes between the 2 groups were compared. Results The length of pushing with the abdominal muscles in the intervention group was significantly shorter than that in the control group （P＜0.01）.There was no significant difference in the length of second stage of labor between the 2 groups （P＞0.05）.The degree of perineal laceration was milder, the rate of episiotomy,bleeding, and neonatal asphyxia, and the postpartum fatigue score, was lower, in the intervention group than in the control group （P＜0.05,P＜0.01）. Conclusion Pushing with the abdominal muscles when the fetus presentation descends 3 cm can effectively shorten the length of pushing, and improve the outcome of maternal delivery.