Screening biomarkers of breast cancer and coronary heart disease (CHD) by bioinformatics methods, and to provide potential targets for the treatment of coronary heart disease induced by breast cancer. The microarray data related to breast cancer and coronary heart disease were downloaded from geo database. The differentially expressed genes were selected by geo2r, and the differentially co expressed genes were obtained according to the intersection of Venn map. Biological function enrichment of GO and KEGG was analyzed by David website, and protein interaction was analyzed by string website and Cytoscape 3.7.2 software. Kaplan Meier plotter and GEPIA were used to analyze the prognosis and verify the gene expression. The results show that: 286 differentially expressed genes were screened from the two data sets, and 45 genes were screened based on the significant mRNA expression level in breast cancer. GO functional enrichment analysis showed that the differentially expressed genes were mainly involved in ubiquitous protein transferase activity, glycoprotein binding, ubiquity protein ligase binding and other biological processes. KEGG analysis showed that the differentially expressed genes were mainly involved in many signaling pathways, such as gap junction, renin secretion, 5-hydroxytryptaminergic synapses, glutamatergic synapses, vascular smooth muscle contraction, platelet activation, and cancer cell proteoglycan. The mRNA expression level and prognosis analysis showed that NLN, POSTN, MAPT, MYO6, MAP1B, FBXO31, KIT and PIK3R1 were involved in the occurrence and development of breast cancer. Conclusion: NLN, POSTN, MAPT, MYO6, MAP1B, FBXO31, KIT, PIK3R1 can be used as potential markers for detecting breast cancer induced coronary heart disease.