Objective: To investigate the expression of blood cadmium and placental 11β-HSD2 in patients with preeclampsia and the effect of traditional Chinese medicine intervention on its expression. Methods: 24 patients with preeclampsia were selected as the case group, and all of them were treated with conventional standard treatment. 12 cases were randomly selected from the routine treatment group, and 12 cases were treated with traditional Chinese medicine on the basis of conventional treatment. The intervention group was treated with traditional Chinese medicine intervention group, and the other 12 cases were non-Chinese medicine intervention group. Twenty normal pregnant women were selected as the normal control group. Blood samples of pregnant women were collected to determine blood cadmium, and placental tissues were collected to determine 11-HSD2 after delivery. The correlation between its expression and preeclampsia was analyzed, and the effect of Huangqi Yumixu Decoction intervention on its expression was discussed. Results: The results of blood cadmium determination in the case group were higher than those in the normal control group, and the results of 11β-HSD2 determination were lower than those in the normal control group (P< 0.05). Pearson linear regression analysis showed that there was a negative correlation between the two (r = -0.459, P<0.05). The results of blood cadmium in the case group taking Astragalus and corn silk were lower than those in the case control group, and 11β-HSD2 was higher than that in the case control group, the difference was statistically significant (P<0.05). Conclusion: Blood cadmium and 11β-HSD2 in patients with preeclampsia showed abnormal changes. The increase of maternal blood cadmium during pregnancy will lead to the decrease of 11β-HSD2 protein expression in placenta. The mechanism may be that PERK siR inhibits the decrease of 11β-HSD2 expression in placental trophoblast cells induced by cadmium. Taking traditional Chinese medicine Astragalus and corn silk can reduce the blood cadmium index of pregnant women and increase the expression of placental 11β-HSD2 protein. The mechanism may be that the drug can improve the clinical efficacy of patients with preeclampsia by reducing blood pressure, improving circulation and eliminating edema.