Abstract: Aerogels with high porosity and low thermal conductivity can absorb sunlight and convert them into thermal energy to heat water, thus are widely used in the field of solar vapor generation to achieve efficient desalination and sewage treatment. In order to improve the evaporation rate of aerogels, PAM-PDA-PEG modified aerogels were prepared by freeze-drying using polyacrylamide (PAM) with good absorbency as substrate, polydopamine (PDA) as hydrophilic modification material and polyethylene glycol (PEG) as dispersant. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet/visible/near-infrared spectrophotometer (UV-vis-NIR), water contact angle and Raman spectroscopy (Raman) were used to characterize the micromorphology, chemical composition, optical properties, hydrophilicity and water state of the modified aerogels. The photothermal conversion performance of PAM-PDA-PEG were also tested by simulated evaporation system. The results show that the photothermal conversion performance of pure PAM is weak, but the modified PAM-PDA-PEG aerogels not only have good absorbance and hydrophilicity, but also contain a large amount of intermediate water which can effectively reduce the energy required for evaporation. Under the light intensity of 1 kW·m^-2, the evaporation rate of PAM-PDA-PEG reaches 2.40 kg·m^-2·h^-1, which is five times that of pure PAM. In addition, desalination and dye removal experiments proved the practical application ability of PAM-PDA-PEG.