Plasmonic nanostructure can efficiently manipulate light on a subwavelength scale, which can break through the optical diffraction limit and significantly enhance the interaction between light and matter. In the study of photoelectric devices based on the plasmonic mechanism, the absorption of light in surface plasmons is usually considered as loss, which needs to be suppressed. However, based on the photothermal effect, the light absorption of plasmonic nanostructure can be effectively utilized and converted into heat. The research of this new type of nano-heat source is a hot topic in the field of plasmonics. In this paper, we review the recent progress of the study of photothermal effects of plasmonic nanostructure, focusing on the physical process of heating effects, and the methods to control the temperature distribution in both the process of heat generation and the process of delivery of heat. Finally, the applications of nano-heat source in the fields of nano-fabrication and broad-spectrum photothermal conversion are also presented.