It is anticipated that solar and thermal energy can be utilized for desalination and wastewater treatment by solar interface water evaporation technology to alleviate water scarcity. Fabricating photothermal interfacial evaporation materials combining low cost, simple preparation method, high water evaporation rate and efficiency is necessary but remains challenging. In this work, polyaniline (PANI) photothermal agent is firstly synthesized by oxidative polymerization, and then a kind of silver nanoparticles@polyaniline/polyvinyl alcohol (AgNPs@PANI/PVA) photothermal sponges is prepared by mechanical foaming, chemical cross-linking, and impregnation reduction method. The incorporation of AgNPs@PANI increases surface hydrophobicity, hence diminishes surface water retention and substantially lowers evaporation enthalpy, which in turn accelerates the water evaporation rate. The results demonstrate that the contact angle is increased from 76.3°±0.3° for PANI/PVA-8.5 to 98.7°±0.2° for AgNPs@PANI/PVA-0.05. The pure water evaporation enthalpy decreases from 2257 J·g-1 to 1547 J·g-1 upon the addition of AgNPs@PANI/PVA under ambient temperature and pressure conditions. The AgNPs@PANI/PVA shows a maximum evaporation rate of 2.28 kg·m-2·h-1 and an outstanding efficiency of 97.9 % under 1 sun irradiation (1 kW·m-2). Moreover, the AgNPs@PANI/PVA exhibits a long-term stability and an effective desalination capability. Therefore, this study introduces a simple method for producing cost-effective, sustainable and efficient photothermal sponge for potential application in seawater desalination.