Background: Breast cancer is a leading cause of cancer-related deaths in women worldwide, posing a significant threat to female health. Therefore, it is crucial to search for new therapeutic targets and prognostic biomarkers for breast cancer patients.Method: Bioinformatics analysis, quantitative real-time PCR (qRT-PCR), and fluorescence in situ hybridization (FISH) were employed to investigate the expression of hsa_circ_002144 in breast cancer. Transwell assay, Western blotting, and cell viability assay were utilized to assess the impact of hsa_circ_002144 on the proliferation, migration, and invasion of breast cancer cells. Additionally, a mouse model was established to validate its functionality. Flow cytometry, WB analysis, enzyme-linked immunosorbent assay (ELISA), qRT-PCR, exosomes isolation, and co-culture system were employed to elucidate the molecular mechanism underlying macrophage polarization.Result: we have discovered for the first time that hsa_circ_002144 is highly expressed in breast cancer. It affected tumor growth and metastasis and could influence macrophage polarization through the glycolytic pathway.Conclusion: This finding provides a new direction for breast cancer treatment and prognosis assessment.