The coupling of light and free electron oscillation on the surface of the metal micro-nano structures results in surface plasmon resonance, exhibiting the local structure of the light field at the sub-wavelength scale, and effectively enhances the interaction between the light and material. Further, the development of research on the photothermal effect of plasmons is reviewed. Subsequently, the mechanism and regulation of photothermal transformation assisted by plasmons are summarized. The regulation and application of the photothermal effect of plasmons in solar vapor generation are introduced. On the one hand, the improvement of the heat utilization rate from block heating to interface heating is studied; on the other hand, the improvement of light absorption efficiency from single frequency absorption to wide spectrum absorption is also studied. Finally, the challenges and opportunities of the photothermal effects of equivalent ionizers are discussed.