Abstract: Potato starch and attapulgite were used as the basic raw materials, and an attapulgite-starch composite aerogel material (ASA) was successfully prepared through starch swelling, freeze-drying, and cross-linking reactions. The obtained ASA possesses a hierarchical porous structure, good thermal insulation performance, and excellent hydrophilicity. A novel photothermal conversion material, PPy-ASA, was prepared by spraying and loading polypyrrole onto the ASA substrate through surface modification. The results show that PPy-ASA has an average light absorption rate of 97.21% in the spectral range of 200-2500 nm. When PPy-ASA is applied to a solar interfacial evaporation system under one-sun irradiation, its evaporation rate reaches 1.5152 kg·m⁻²·h⁻¹. Multiple cycling tests and simulated saline water evaporation experiments confirm that PPy-ASA has good structural stability and excellent salt resistance. In addition, the composite material can be effectively applied to seawater desalination and organic dye wastewater treatment, and the removal rates of salt ions and organic dye pollutants in the test samples remain consistently above 99%.