The goal of this research is to explore the anticancer effects of α-enolase targeted peptide (ETP) modified oxaliplatin-loaded Fe3O4 nanoparticles (ETP-PtFe NPs) and their synthesis, characterization, biological function, and characterization on breast cancer. The ETP-PtFe NPs were studied using transmission electron microscopy, dynamic light scattering, zeta potential analysis, and ultraviolet absorption spectroscopy. Nanocomplexes’ cytotoxicity and cell cycle distribution were studied utilizing flow cytometry tests in a total of eight trials. A unilateral subcutaneous tumor-bearing rat was created to test the anticancer effects of ETP-PtFe NPs In Vivo. In combination with near-infrared light irradiation, ETP-PtFe suppressed the proliferation of 4TI and MDA-MB-231 breast cancer cells much more than the pure material group in the CCK8 experiment. ETP-PtFe and NIR light irradiation significantly suppressed 4TI and MDA-MB-231 breast cancer cells in the G2/M phase of the cell cycle compared to the pure material group. This study found that ETP-PtFe combination with near infrared light irradiation was more effective In Vivo against tumors in mice with unilateral subcutaneous tumors than normal saline combined with near infrared light irradiation. The anticancer and photothermal effects of the ETP-PtFe nanocomposite In Vitro and In Vivo provide a promising notion and technique for non-invasive early diagnosis and non-surgical treatment of breast cancer’s primary tumor.