In order to evaluate the photothermal effect of CuS@Cu2S nanoparticles, photothermal temperature curves and images were observed by an infrared camera, and photothermal efficiency was calculated by linear fitting. The results show that CuS@Cu2S nanoparticles have higher temperature increase under 808 nm laser irradiation, which can be proved by near-infrared (NIR) thermal images. Moreover, high photothermal conversion efficiency of CuS@Cu2S can be adjusted by the content of Cu2S.