3D porous interfacial carbon materials have high-efficiency in water evaporation at the solution interface, which have important application prospects in the field of outdoor solar driven seawater desalination. Polyvinylalcohol (PVA) was used to modify polyurethane sponge with hydrophilicity, and multi-wall carbon nanotubes / polydimethylsiloxane (CNTs/PDMS) composite dispersion was sprayed on the front of the PVA modified sponge to obtain a 3D porous Janus solar driven interfacial evaporator with the front side super-hydrophobic and the backside hydrophilic. The wide band high solar absorptivity (> 95%) and the photothermal conversion effect of CNTs endow the sponge with interfacial water evaporation capability. The rough structure of the CNTs and the low surface energy property of the PDMS endow the photothermal absorption layer with superhydrophobicity. Thus, the modified polyurethane sponge can not only float on the water surface, but also have self-cleaning and salt blocking effects. Hydrophilicity of the PVA helps the modified polyurethane sponge form excellent water transport channels. The test results show that the evaporation rate of the modified polyurethane sponge with 3D porous structures as an interfacial evaporator can reach 1.80 kg m-2 h-1 under one solar intensity (1 kW m-2) for evaporation of simulated seawater (3.5 wt% salinity).