To explore the change of the serum antioxidant level of pregnant women with placental abruption, and to study its correlation with the severity of placental abruption and the postpartum hemorrhage of the women. Methods: 104 pregnant women with placental abruption from January 2019 to March 2022 were selected in study group. 120 healthy pregnant women who came to hospital for prenatal examination were selected in control group during the same period. The levels of serum total superoxide dismutase (TSOD), uric acid (UA), and albumin (ALB) of the women in the two groups were detected and were compared between the two groups. Pearson correlation and Spearman correlation were used to analyze the correlation between the serum antioxidant level of the women with placental abruption and their severity of disease and the amount of postpartum hemorrhage. Receiver operator characteristic (ROC) curve was used to analyze the predictive efficacy of the serum antioxidant level of the women for their postpartum hemorrhage. Results: The levels of serum TSOD (78.66±6.69 U/ml) and UA (358.62±35.62μmol/L) of the women in the study group were significantly higher than those (65.47±5.10 U/ml and 265.69±25.64μmol/L) of the women in the control group. The level of ALB (34.20±3.36 g/L) of the women in the study group was significantly lower than that (56.65±5.62 g/L) of the women in the control group. The levels of serum TSOD and UA of the women with degree Ⅱ placental abruption were significantly higher than those of the women with degree 0-Ⅰ placental abruption, but the level of ALB of the women with degree Ⅱ placental abruption was significantly lower. The serum TSOD and UA levels of the women with postpartum blood loss >300 ml were significantly higher than those of the women with postpartum blood loss ≤300 ml, but the ALB level of the women with postpartum blood loss >300 ml was significantly lower (all P<0.05). The severity of placental abruption of the women was positively correlated with their serum TSOD and UA levels, and was negatively correlated with their serum ALB level. The amount of postpartum hemorrhage of the women with placental abruption was positively correlated with their serum TSOD and UA levels, and was negatively correlated with their serum ALB level (all P<0.005). ROC curve showed that the area under the curve, the cutoff value, the sensitivity, and the specificity of the ALB level of the women for diagnosing their postpartum hemorrhage were 0.710, 32.24g/L, 72.2%, and 80.63%, respectively. The area under the curve, the cut-off value, the sensitivity, and the specificity of the UA level of the women for diagnosing their postpartum hemorrhage were 0.721, 360.30μmol/L, 75.6%, and 85.6%, respectively. The area under the curve, the cutoff value, the sensitivity, and the specificity of the TSOD level of the women for diagnosing their postpartum hemorrhage were 0.730, 80.66U/ml, 76.7%, and 89.0%, respectively. Conclusion: The serum TSOD and UA levels of the pregnant women with placental abruption increase, and the ALB level of the women decreases, which are related to the severity of the placental abruption and the amount of postpartum hemorrhage of the women.