Objective To investigate the application of gemstone spectral imaging (GSI) in the diagnosis of lymph nodes metastasis and blood supply in patients with breast infiltrating ductal carcinoma. Methods 63 patients with pathologically confirmed breast infiltrating ductal carcinoma admitted to our hospital from January 2016 to August 2018 were selected as subjects. All patients underwent axillary lymph node dissection, and the nodes were divided into metastasis group (n=42) and non-metastasis group (n=98) according to axillary lymph node metastasis. All cases underwent GSI scan, and the images were retrospectively analyzed using GSI viewer on ADW 4. 6 work station. The KeV-CT value curve was generated by the computer automatically, the iodine-based value and CT value of each lymph node and the corresponding strata of the artery were recorded. Then the SPSS22. 0 software was used for statistical analysis. Results In 40-70 KeV area, the slope of KeV-CT value curve of metastasis group was significantly lower than that of non-metastasis group [(3.65±0.52) vs (4.98±1.28), P=0.13], and the curve was flattened above the 70 KeV area. The slope of KeV-CT value curve, Iodine-based value and the normalized Iodine-based value of metastasis group were significantly lower than those of non-metastasis group (P<0.01), while no statistical difference was found of the normalized CT value between groups (P>0.05). The areas under the ROC curve (AUC) of slope of KeV-CT value curve, Iodine-based value and the normalized Iodine-based value were 0.801, 0.779 and 0.884, respectively, indicating that the normalized Iodine-based value had the highest diagnosis rate. The blood supply of lesions was clearly displayed. Conclusion GSI as a non-invasive examination is worthy of promotion in the detection of lymph nodes metastasis and blood supply in patients with breast infiltrating ductal carcinoma.