To improve the therapeutic efficacy of cardamonin (CRD) in the treatment of breast cancer, Lycium barbarum polysaccharide (LBP) was selected as a nanocarrier for CRD and IR780 to prepare CRD-IR780@LBP nanoparticles (NPs) via antisolvent precipitation. CRD-IR780@LBP NPs demonstrated superior characteristics, such as sustainable drug release, high photothermal conversion, and good antitumor efficacy and secretion levels of cytokines (TNF-α, IL-6 and IL-2). The IC50 value of CRD-IR780@LBP NPs was 2.31 μg/mL, which was significantly lower than that of the pure CRD group (P < 0.0001). The tumor inhibition rate of CRD-IR780@LBP NPs was 80.03 %, which was a 1.58-fold increase compared to that of PTX injection. Furthermore, the ELISA results suggested that LBP can exert therapeutic effects by upregulating the expression levels of TNF-α, IL-6 and IL-2 (P < 0.01) without causing any apparent adverse effects on major tissues and organs. In conclusion, the CRD-IR780@LBP NPs prepared in this study can enhance the therapeutic efficacy of CRD against breast cancer via multiple synergistic anti-tumor mechanisms.