In this paper, a new type of floating solar evaporator with a three-layer composite structure has been successfully fabricated, with the carbon nanotube (CNT) as the photothermal layer, the silver nanowires as the preheating layer and the glass fibers as the insulation layer. The solar evaporator exhibited excellent solar absorption and photothermal conversion properties, and the surface temperature of the dried evaporator could reach 106 degrees C under one solar irradiation intensity. Importantly, the pure water evaporation rate and the solar evaporation efficiency of this evaporator were 1.70 kg/m(2) h and 95%, respectively. Based on the multi-layer composite structure of the evaporator, the addition of the silver nanowires as the preheating layer effectively reduced the loss of the thermal energy of the photothermal layer as the heat source and the evaporation region. The purpose of this study is to improve the solar energy efficiency by reducing heat conduction losses through the design of evaporators.