Coal tar pitch-based porous carbon is prepared using coal tar pitch as the raw material and CaCO₃ as the pore-making agent, after undergoing oxidation modification with a mixed acid, it is utilized as a light absorber (NSCTP). Subsequently, it is combined with polyvinyl alcohol (PVA) to construct a coal tar pitch-based porous carbon hydrogel interfacial water evaporator (NSCTP@PVA). A systematic study is carried out to examine the microstructure, light-absorption properties, hydrophilicity, photothermal conversion characteristics, and solar-driven interfacial water evaporation performance of light absorbers and evaporators. The results show that the NSCTP@PVA hydrogel evaporator exhibits excellent water transport characteristics and photothermal conversion efficiency, with a water evaporation rate of 1.28 kg·m^-2·h^-1 and photothermal conversion efficiency of 74.16% under 1 kW·m^-2 light intensity. Even after long cycling in a 3.5 wt% NaCl solution and simulated brine, the evaporation rate remains stable at 1.20 kg·m^-2·h^-1, demonstrating remarkable cycling stability and evaporation performance. Furthermore, the NSCTP@PVA hydrogel evaporator shows excellent performance in seawater desalination, brine purification, dye removal, and industrial wastewater treatment.