Objective To explore the application value of color Doppler ultrasound in detecting uterine artery blood flow spectrum at middle and advanced stage in pregnancy-induced hypertension syndrome (PIH).Methods A total of 100 pregnant women at middle and advanced stage admitted to Fuzhou Maternal and Child Health Center from May 2018 to April 2020 were selected.They were divided into the normal pregnancy group (n=50) and the PIH group (n=50) according to the follow-up results,and they were all provided with color Doppler ultrasound blood flow spectrum test.The blood flow spectrum test results,the positive rate of each index and the level of each index of patients in different types were compared between the two groups.Results Resistance index (RI),arterial pulsatility index (PI),the ratio of fetal umbilical artery systolic blood pressure to diastolic blood pressure (S/D) in the PIH group were higher than those in the normal pregnancy group (P＜0.05).The positive rates of RI,PI and S/D in the PIH group were higher than those in the normal pregnancy group (P＜0.05).The RI,PI and S/D values of patients with eclampsia were higher than those of patients with preeclampsia and hypertension during pregnancy (P ＜0.05).The RI,PI,and S/D values of preeclampsia were higher than those of hypertension during pregnancy (P＜0.05).Conclusion Color Doppler ultrasound detection of uterine artery blood flow spectrum at middle and advanced stage pregnancy has a good application value in PIH,which can provide a good basis for clinicians to predict and evaluate PIH,and is worthy of promotion.