To analyze the value of the second to the first peak blood flow velocity (B/A) ratio of the ophthalmic artery and the systolic to diastolic velocity (S/D) ratio of the uterine artery of pregnant women during the second trimester of pregnancy for predicting their preeclampsia (PE). Methods: 203 pregnant women who had received prenatal examinations and had delivery in hospital from January 2021 to February 2023 were collected retrospectively. Based on the PE occurrence or not, these women were divided into study group (41 women with PE) and control group (162 women with normal pregnancy). The B/A ratio of the ophthalmic artery and the S/D ratio of the uterine artery of the women in both groups were measured during 15-20 gestational weeks. Receiver operating characteristic (ROC) curve was drawn to analyze the predictive value of the B/A ratio and the S/D ratio of the pregnant women for their PE occurrence. Results: The rates of the perinatal mortality, the neonatal intensive care unit transfer and the maternal complications of the women in the study group were significantly higher than those of the women in the control group. The B/A ratio of ophthalmic artery (0.71±0.15) and the S/D ratio of uterine artery (3.27±0.76) of the women in the study group were significantly higher those (0.49±0.11 and 1.99±0.53) of the women in the control group (all P<0.05). The area under the curve of the B/A ratio of ophthalmic artery and the S/D ratio of uterine artery of the pregnant women for their PE occurrence were 0.945 and 0.875, the sensitivity of which were 87.8% and 78.1%, and the specificity of which were93.2% and 89.5% (P>0.05). Conclusion: Both the B/A ratio of the ophthalmic artery and the S/D ratio of the uterine artery of the pregnant women with PE during 15-20 gestational weeks are higher than those of the normal pregnant women, and both have better predictive efficacy for the PE occurrence of the pregnant women, and which can be applied in clinical practice.