Objective To analyze the relationship between color doppler ultrasound parameters and insulin sensitivity index (ISI) and clinical efficacy in rats with polycystic ovary syndrome (PCOS) combined with hyperinsulinemia (HI). Methods 140 3-week-old female SD rats of SPF grade were selected and randomly divided into two groups. The PCOS combined with hi rat model (Study Group) and PCOS without hi rat model (control group) was prepared respectively. After successful modeling, the rats were examined by color doppler ultrasound, and the total area (TA), ovarian volume (OV), interstitial area (SA), vascularization index (VI), blood flow index (FI), vascularized blood flow index (VFI), peak systolic blood flow velocity (PSV), peak diastolic blood flow velocity (PDV), resistance index (RI), and ovarian interstitial artery pulsation index (PI) were compared between the two groups. Fasting insulin (fins) and fasting blood glucose (FPG) were measured in rats" fasting venous blood at the same time, and ISI was calculated. Pearson correlation analysis was used to analyze the correlation between color doppler ultrasound parameters and ISI in the study group. The rats in the study group were treated with metformin by intragastric administration. According to the therapeutic effect, the rats in the study group were divided into the good effect group and the poor effect group. The color doppler ultrasound parameters of the two groups were compared, and the receiver operating characteristic curve (ROC) was drawn to analyze the value of color doppler ultrasound parameters in evaluating the curative effect of PCOS combined with hi rats. Results: 65 rats with PCOS and hi were successfully established in the study group, and 60 rats without PCOS and hi were successfully established in the control group. The body weight, body mass index, systolic blood pressure, diastolic blood pressure, Ta, OV, SA, VI, fi, VFI, PSV, PDV, fins and FPG of the study group were higher than those of the control group, while RI, PI and ISI of the study group were lower than those of the control group, and the differences were statistically significant (P<0.05). Pearson correlation analysis showed that color doppler ultrasound parameters TA and SA were negatively correlated with ISI (r=-0.501, -0.492, P<0.05), and ovarian RI and PI were positively correlated with ISI (r=0.504, 0.485, P<0.05). In the group with good curative effect, Ta、OV、SA、VI、FI、VFI、PSV、PDV、 Low density lipoprotein cholesterol, FPG, fins, LH, FSH were lower than those in the poor efficacy group, RI, PI were higher than those in the poor efficacy group, the difference was statistically significant (P<0.05). ROC curve analysis showed that the sensitivity and specificity of color doppler ultrasound parameters combined with clinical efficacy were 90.9% and 90.2%, respectively, and the area under the curve (AUC) was 0.901. Conclusion Color doppler ultrasound parameters are closely related to ISI and clinical efficacy of PCOS combined with hi rats, which can predict the clinical efficacy of such patients to a certain extent.