Objective To investigate the imaging findings of breast cancer and the relationship with lymph node metastasis. Methods The imaging data of 120 patients with breast cancer in our hospital were analyzed retrospectively. All the patients were examined by B-mode ultrasonography and confirmed by surgery and pathology. They were divided into the metastasis group and non-metastasis group. Imaging findings of the two groups were analyzed, and the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate of the imaging findings were also analyzed. Imaging findings of lymph node metastasis were discussed. Results Pathological examination confirmed that there were 38 cases in metastasis group and 82 cases in nonmetastasis group, while there were 42 cases and 78 cases diagnosed by ultrasonography. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of B-mode ultrasonography in the diagnosis of lymph node metastasis of breast cancerwere 84.2％, 87.8％, 86.7％, 76.2％, 92.3％. The imaging findings of patients with metastasis included eccentric thickening as the main cortical form with axillary lymph node metastasis, peripheral type blood flow and even internal echo. The imaging findings of patients without metastasis included stenosis type cortex, lymphatic typeblood flow and internal homogeneously hypoechoic or anechoic. Conclusion Ultrasonography of patients with breast cancer can be used as a criterion for diagnosis of lymph node metastasis, which provides references for the treatment of breast cancer.