Objective To explore the value of superb microvascular imaging (SMI) combined with advanced dynamic flow (ADF) in guiding the classifications of breast Breast Imaging Reporting and Data System (BI-RADS) class 4 micronodules with diameter of ≤10 mm. Methods A total of 78 female patients undergoing breast examination and surgery in the hospital were enrolled as the research objects between December 2020 and December 2023. There were 81 lesions with diameter of ≤10 mm detected by ultrasound. All patients underwent SMI combined with ADF examination. According to the results of postoperative pathological biopsy, 78 patients (81 lesions) were divided into benign group (47 cases, 47 lesions) and malignant group (31 cases, 34 lesions). The diagnostic efficiency of SMI, ADF and combined detection, and the evaluation value of of SMI and ADF for Adler grading of breast BI-RADS class 4 micronodules with diameter of ≤10 mm were analyzed. Results According to postoperative pathological results, 81 lesions were divided into benign group (47 lesions) and malignant group (34 lesions). SMI, ADF and combined detection showed that there were 37, 40 and 48 malignant micronodules, with detection rates of 45.68%, 49.38% and 59.26%, respectively. The sensitivity, specificity, accuracy, and Kappa coefficient of SMI and ADF in the diagnosis of malignant micronodules were (82.35%, 80.85%, 81.48%, 0.632) and (73.53%, 68.09%, 70.37%, 0.406), respectively. The sensitivity and Kappa coefficient of combined detection were higher (97.06%, 0.651). In SMI and ADF examinations, blood flow signals of grade 0 and grade I were more common in benign lesions, and blood flow signals of grade II and grade III were more common in malignant lesions. The higher the Adler grading, the higher the malignant rate of breast BI-RADS class 4 micronodules with diameter of ≤10 mm (P<0.05). There were significant differences in blood flow grading between benign and malignant lesions by SMI and ADF (P<0.05). Conclusion SMI combined with ADF can improve the diagnostic efficiency of malignant breast BI-RADS class 4 micronodules with diameter of ≤10 mm. The higher the Adler grading, the higher the malignant rate.