Objective: To observe the effect and safety of fentanyl combined with pentazocine in post cesarean section analgesia. Methods: A total of 136 cases of pregnant women in our hospital undergoing cesarean section were selected as the object of our study, then divided into observation group and control group, 68 cases in each group. The two groups were taken spinal epidural analgesia then undergoing cesarean section, after cesarean section intravenous patient-controlled analgesia. Results: Comparison of two groups of postoperative VAS score, the difference was not statistically significant (P=0.145); there wasn’t significant differences between the two groups VAS score at each time point (P=0.107); there wasn’t interaction between the analgesic and time (P=0.33). The Ramsay score of the observation group were lower than those of control group, the difference has statistical significance (P=0.042). There was significant differences between the two groups Ramsay score at each time point (P=0.027); There was interaction between the analgesic and time (P=0.031). There wasn’t statistical difference between maternal analgesia pump pressing numbers of the two groups (P=0.137). The adverse reaction incidence of observation group was lower than that of control group, but there was no significant difference (P=0.511). Conclusion: It is effective using Fentanyl combined with pentazocine in Post Cesarean section analgesia, and don’t increase the adverse reaction.