In present work, an enhanced solar distillation system that combined a concentrating optical engineering and nanofluid-based spectral splitting PV/T technique is proposed to overcome the drawbacks of conventional solar distillation system. In such a system, gold and silver nanoparticles with selectively spectral absorption are added into water to absorb solar radiation that can't be efficiently utilized by PV cells, and convert them into heat. The rest of solar radiation through nanofluid is converted into electricity to provide power to a fan, which is used to transport steam to an external condenser. The optical performance of the concentrated distiller is investigated by a simulation and experimental test. The optical and thermal properties of gold and silver nanoparticles are characterized, and the mean absorptivity and transmittance of the nanofluids are calculated and compared with pure water. The experimental results confirmed the improvement of nanofluid-based spectral splitting PV/T technique to solar distillation. In comparison with a conventional system, the water yield of the enhanced systems with gold and silver nanoparticles of mere 26 ppm concentration increase by 79.9% and 69.4%, respectively. The thermal efficiency of the enhanced systems with gold and silver nanoparticles also increase by 6.8% and 4.8%, respectively. Such a performance is mainly owing to two effects in the enhanced system. On the one hand, nanoparticles promote the absorption of water to solar energy, and then raise the temperature of water in the evaporator. On the other hand, the use of an external condenser in the enhanced system not only enhances the condensation of steam, but also improves the transmittance of distiller cover. Moreover, gold nanoparticle has more obvious improvement to water productivity than silver nanoparticle, but the PV efficiency of the enhanced system with gold nanofluid is lower than that of silver nanofluid. Therefore, the spectral characteristics of nanofluid have a significant influence for the performance of the enhanced distillation system.