This paper studies the light-induced heating and the temperature distribution of Au nanoparticulate material by using the finite element software COMSOL combined with the two-temperature model, where the effect of dependent scattering of Au nanoparticles is studied, and the transfer mode of energy in the composite medium in photothermal effect is also discussed. The results show that the two-temperature model and the Fourier heat conduction law can be combined together to describe the temperature changes of the nanoparticles and the surrounding medium; Compared with independent scattering particles, the photothermal effect is influenced by the coupling phenomenon between dependent scattering particles, and the interparticles coupling effect depends on their distance.