Breast cancer has become one of the common malignant tumors in women in China, and the incidence rate accounts for 7% to 10% of systemic malignant tumors. Some studies have shown that there is a significant difference in overall survival and recurrence-free survival between those with negative and positive axillary lymph node metastases in breast cancer patients, and the probability of positive lymph nodes is an independent prognostic indicator affecting the overall survival of breast cancer patients with positive axillary lymph nodes. Accurate assessment of axillary lymph node metastasis status in breast cancer patients before treatment can lead to accurate clinical treatment plans for patients and is also important for determining prognosis. Objective: To investigate the diagnostic value of breast MRI and color ultrasound on axillary lymph node metastasis. Methods: To retrospectively analyze the clinical data of 136 breast cancer patients with preoperative clinical stage I-IIIA who had undergone breast MRI, and to analyze the diagnosis of axillary lymph nodes by MRI and color ultrasound and the postoperative pathological results. Results: The sensitivity, specificity and accuracy of breast MRI in the diagnosis of axillary lymph node metastasis were 83.3%, 88.6% and 86.3%, respectively, while the sensitivity, specificity and accuracy of color ultrasound diagnosis were 73.1%, 76.7% and 75.o%, respectively. The sensitivity, specificity and accuracy of breast MRI in diagnosing the status of axillary lymph node metastasis in early breast cancer were better than those of breast ultrasound. The sensitivity, specificity and accuracy of breast MRI in evaluating axillary lymph nodes in patients aged ≥50 years were 70.0%, 77.8% and 75.0%, respectively, while the sensitivity, specificity and accuracy in patients <50 years were 85.7%, 92.3% and 88.9%, respectively. The sensitivity, specificity and accuracy of breast mri in diagnosing the status of axillary lymph node metastasis in patients with early breast cancer aged <50 years were better than those patients aged/>50 years. The sensitivity, specificity and accuracy of axillary lymph node metastasis status in breast cancer patients were better than/–> CONCLUSION: Breast MRI is of great value in assessing the status of axillary lymph node metastasis in early breast cancer, especially in early breast cancer patients <50 years of age, and can provide a scientific basis for the formulation of accurate clinical treatment plans.