Breast　cancer　(BC)　is　one　of　the　most　devastating　cancers,　with　high　morbidity　and　mortality,　among　the　female　population　worldwide.　In　BC,　mesenchymal　stem　cells　(MSCs),　as　pluripotent　stromal　stem　cells,　play　a　significant　role　in　TME　formation　and　tumor　progression.　Recently,　an　increasing　number　of　studies　have　demonstrated　that　extracellular　vesicles　(EVs)　are　essential　for　the　crosstalk　between　MSCs　and　BC　cells.　MSC-derived　EVs　(MSC-EVs)　can　deliver　a　diversity　of　molecules,　including　lipids,　proteins,　and　nucleic　acids,　etc.,　to　target　cells,　and　produce　corresponding　effects.　Studies　have　demonstrated　that　MSC-EVs　exert　both　inhibitory　and　promotive　effects　in　different　situations　and　different　stages　of　BC.　Meanwhile,　MSC-EVs　provide　novel　therapeutic　options　for　BC,　such　as　EVs　as　carriers　for　drug　delivery.　Therefore,　in　this　review,　we　summarize　the　role　of　MSC-EVs　in　BC　progression　and　application　in　clinical　treatment,　in　the　hope　of　providing　a　basis　for　further　research.