Abstract: Photothermal conversion is the process of converting solar energy into thermal energy. This allows for the use of solar energy, a clean and renewable resource, to alleviate energy scarcity. Carbon aerogel materials with a highly developed pore structure, excellent light capture, and high photothermal conversion efficiency are currently the research hotspots in the field of photothermal conversion. This paper outlines the principles of photothermal conversion for various photothermal materials, It then discusses the research progress of different types of carbon aerogels, including graphene aerogel, carbon nanotube aerogel, biomass-based carbon aerogel, and polymer-based carbon aerogel, as photothermal materials. Finally, it introduces the applications of carbon aerogel as photothermal materials in solar water evaporation, thermal energy storage, photothermal catalysis, photothermal therapy, and photothermal de-icing.