Objective To explore the relationship of color superb microvascular imaging (cSMI) with microvessel density of uterine fibroids and its application in the efficacy evaluation of high-intensity focused ultrasound (HIFU). Methods Totally 89 patients with uterine fibroids in the hospital from February 2019 to October 2022 were selected. The blood flow of fibroids was detected by cSMI and color Doppler flow imaging (CDFI) respectively, and the consistency of the two detection methods was compared. Among the patients, 68 cases who met the indications of HIFU were treated with HIFU. The clinical efficacy before and after treatment and blood flow of fibroids after treatment were compared among patients with different blood flow grades. Results cSMI detected 22 cases of grade 1 (24.72%), 51 cases of grade 2 (57.31%) and 16 cases of grade 3 (17.97%), and CDFI detected 30 cases of grade 1 (33.71%), 41 cases of grade 2 (40.07%) and 18 cases of grade 3 (20.22%). The consistency of the two detection methods in evaluating the blood flow of uterine fibroids was moderate (Kappa=0.490, P<0.05). The number of patients with grade 2 blood flow detected by SMI was more than that of CDFI. The end-diastolic blood flow velocity and peak systolic blood flow velocity of patients with different blood flow grades were gradually increased with the increase of blood flow grade (P<0.05), and the resistance index of patients with blood flow grade 3 was higher than that of patients with blood flow grade 1 (P<0.05). Spearman correlation analysis showed that end-diastolic flow velocity, peak systolic flow velocity and resistance index were positively correlated with blood flow grading (P<0.05), and the correlation coefficient r values were 0.684, 0.635 and 0.324 respectively. Among 68 patients after HIFU treatment, the end-diastolic blood flow velocity, peak systolic blood flow velocity and resistance index were significantly decreased after treatment compared to before treatment (P<0.05). There was a significant difference in the volume of uterine fibroid before treatment (P<0.05). The volume of uterine fibroid in patients with blood flow grade 2 or 3 was larger than that in patients with blood flow grade 1 (P<0.05).68 patients were treated with HIFU, and 49 cases (72.06%) were markedly effective and 19 cases (27.94%) were effective, with the total effective rate of 100.00%. Among the patients with different blood flow grades, the higher the blood flow grade, the larger the uterine fibroid volume after treatment, and the uterine fibroid volume reduction rate and ablation rate were gradually decreased with the increase of blood flow grade (P<0.05). After treatment, there were 36 cases (52.94%) of blood flow grade 0, 27 cases (39.71%) of blood flow grade 1 and 5 cases (7.35%) of blood flow grade 2 among 68 the patients. Conclusion SMI can effectively evaluate the blood flow of patients with uterine fibroids, and can be used to evaluate the clinical efficacy of HIFU treatment