The present disclosure provides a method for predicting breast cancer prognosis, including the following steps: (a) detecting the expression level of pyruvate kinase; (b) detecting the expression level of O-linked β-N-acetylglucosamine; and (c) evaluating a clinical treatment score post-5 years, wherein when the expression level of the pyruvate kinase and the expression level of the O-GlcNAc are detected as high expression levels, and the clinical treatment score post-5 years is evaluated as a high score, it means that the prognosis of the breast cancer is poor. The present disclosure also provides a kit for predicting breast cancer prognosis. |