The development of innovative therapeutic strategies that combine multiple treatment modalities is essential for effective cancer therapy. In this study, we engineered berberine (BER)-loaded mesoporous polydopamine (MPDA) nanoparticles (BER-MPDA) to enhance anti-tumor efficacy through synergistic chemotherapy and photothermal therapy (PTT). The mesoporous structure of MPDA allowed for a high loading capacity of BER, a natural isoquinoline alkaloid with known anticancer properties. Upon near-infrared laser irradiation, BER-MPDA exhibited marked photothermal conversion efficiency, leading to effective tumor cell ablation. Both in vitro and in vivo experiments indicated that the combined treatment of BER-MPDA with near-infrared laser irradiation resulted in superior tumor inhibition compared to monotherapy. The synergistic effect was attributed to the enhanced cellular uptake and the simultaneous induction of chemo- and photothermal cytotoxicity. Our findings suggest that BER-MPDA represents a promising platform for multimodal cancer therapy, offering a potent approach to overcoming the limitations of conventional chemotherapy and PTT.