The novel metal(II)-based complexes HA-Cu, HA-Co, and HA-Ni with phenanthroline, sulfamethazine, and aromatic−aromatic coupled disulfamethazines as ligands were synthesized and characterized. HA-Cu, HA-Co, and HA-Ni all showed a broad spectrum of cytotoxicity and antiangiogenesis. HA-Cu was superior to HA-Co and HA-Ni, and even superior to DDP, showing significant inhibitory effect on the growth and development of tripe-negative breast cancer in vivo and in vitro. HA-Cu exhibited observable synergistic effects of antiproliferation, antiangiogenesis, anti-inflammatory, pro-apoptosis, and cuproptosis to effectively inhibited tumor survival and development. The molecular mechanism was confirmed that HA-Cu could downregulate the expression of key proteins in the VEGF/VEGFR2 signaling pathway and the expression of inflammatory cytokines, enhance the advantage of pro-apoptotic protein Bax, and enforce cuproptosis by weakening the expression of FDX1 and enhancing the expression of HSP70. Our research will provide a theoretical and practical reference for the development of metal-sulfamethazine and its derivatives as chemotherapy drugs for cancer treatment.