Breast cancer, as a malignant tumor with easy metastasis and poor prognosis, threatens the health of women around the world. Increasing studies have shown that the Bcl-2 family of apoptosis-related proteins is often expressed abnormally in breast cancer. The Bcl-2 homology 3 (BH3) mimetic peptide can bind and neutralize Bcl-2, preventing its binding to the apoptosis "effector" proteins Bak and Bax, thereby promoting the apoptosis process. However, there is a lack of effective intracellular delivery system for BH3 to exert its biological activity. Therefore, this study utilized an activatable supercharged polypeptide (ASCP) tumor-targeted delivery platform based on pH and protease response to achieve the targeted release of BH3 at the tumor site. Ultimately, intracellular delivery of BH3 was achieved and induced apoptosis of breast tumor cells, preventing the development of breast cancer.