Abstract: Breast cancer bone metastasis disrupts bone metabolism, enhancing osteogenic differentiation can improve the metastatic microenvironment and treatment outcomes. Thus, developing agents that inhibit breast cancer and promote osteogenesis may offer new strategies. Tripterygium wilfordii possesses antitumor and bone-regulating properties, but its toxicity limits clinical application. Here, a carbon dot was synthesized from Tripterygium wilfordii (Tripterygium wilfordii carbon dots, T-CDs) and characterized by spectral analysis, dynamic light scattering, and transmission electron microscopy. T-CDs exhibited a near-spherical morphology with a lattice spacing of 0.20 nm, an average size of 5.38 nm, and a ζ potential of -8.46 mV. The surface was rich in -OH, C=O, and C=C groups, with ultraviolet absorption at 280 nm. T-CDs disrupted redox homeostasis in breast cancer cells, inducing ferroptosis and immunogenic cell death. Moreover, T-CDs modulated cytokine secretion and promoted osteogenic differentiation, offering potential for the treatment of breast cancer and its bone metastasis.