Objective To explore inhibition of melanoma growth by photothermal therapy mediated with dopamine-coated gold nanoparticles (Au@PDA). Methods Firstly, spherical gold nanoparticles (Au) and Au@PDA were prepared for photothermal therapy (PTT). Cell survival rate was test by CCK-8, cell migration was measured by scratch test, and the apoptosis was detected by Annexin V/PI staining in vitro. The secretion of HMGB1 from cells after photothermal therapy was measured by ELISA to confirm the influence on tumor cell immunity. Further, the tumor inhibition and anti-tumor immune response activation by Au@PDA mediated PTT were observed in vivo. Finally, the effects of nanoparticles on the major organs were observed by HE staining. Results The Au and Au@PDA were both successfully prepared. Au@PDA could significantly induce cell apoptosis, inhibit cell proliferation and migration, increase the secretion of HMGB1 after irradiated with 808nm laser. The animal experiment results showed that the photothermal therapy mediated with Au@PDA could significantly lead tumor tissue necrosis, increase the number of infiltration T cell in tumor tissue, active the anti-tumor immune response, and finally inhibit tumor growth. HE staining results showed the nanoparticles had no obvious damage to the main organ. Conclusion Photothermal therapy mediated by Au@PDA can not only kill tumor cells through directly heat energy, but also activate the anti-tumor immune response to inhibit tumor growth