To compare the analgesia effectiveness of 0.25% and 0.15% ropivacaine used in the bilateral transversus abdominis plane block guided by B-ultrasound of the women after cesarean section. Methods: 90 pregnant women who wanted cesarean section were selected and were randomly divided into group A (45 women with 0.15% ropivacaine for analgesia used in the bilateral transversus abdominis plane block) and group B (45 women with 0.25% ropivacaine for analgesia) from September 2020 to September 2023. The postoperative recovery situation, the postoperative analgesia, the dynamic and static pain scores of VAS, the levels of oxidative stress indexes, such as cortisol (COR) and C-reactive protein (CRP), and the adverse reactions rate of the women were compared between the two groups. Results: The spontaneous urination time (17.23±2.26h), the first ambulation time (11.32±2.56h), the number of pressing analgesic pump in 24 h (3.37±0.59 times) and the amount of analgesic pump fluid used (50.02±5.34) of the women in group B were significantly less than those (25.37±1.83h, 15.19±2.37 and 6.28±0.81 times) of the women in group A. The effective analgesia time (41.33±3.18h) and the time of the first pressing analgesia pump after operation (13.37±3.50h) of the women in group B were significantly higher than those (29.62±1.87h and 6.38±2.08h) of the women in group A. The VAS scores of the women in the two groups at dynamic and static 12h and 24h after operation were significantly lower than those at 1h after operation, and which (4.22±0.26 points and 3.01±0.35 points, and 3.15±0.21 points and 2.16±0.24 points) of the women in group B were significantly lower than those (5.37±0.24 points and 3.89±0.17 points, and 3.62±0.19 points and 2.95±0.28 points) of the women in group A. The levels of COR and CRP of the women in the two groups at 12h after operation were significantly higher than those before operation, but which (643.47±20.49 nmol/L and 18.79±2.74 mg/L) of the women in group B were significantly lower than those (757.43±17.49 nmol/L and 27.54±3.83 mg/L) of the women in group A (all P<0.05). There was no significant difference in the adverse reactions rate (15.6% vs.11.1%) of the women between the two groups (P>0.05). Conclusion: 0.25% ropivacaine used in the bilateral transversus abdominis plane block guided by B-ultrasound of the women can significantly enhance their postoperative analgesic effect, reduce their postoperative stress reaction, and without the increase of the adverse reactions.