Solar steam generation has received tremendous attention recently due to the increasing demand for fresh water. In this study, carbon black (CB) and antimony doped tin oxide (ATO) hybrid nanofluid were prepared to improve the performance of the solar desalination system. The long-term stability of CB-ATO nanofluids enables good operation during solar steam generation. The optical properties of hybrid nanofluids were investigated systematically and showed that hybrid nanofluids significantly enhanced the solar energy utilization ability compared with one-component nanofluids. Furthermore, solar evaporation experiments of hybrid nanofluids were carried out under one sun using solar irradiation simulator, the evaporation efficiency was enhanced by about four times than pure water with the addition of nanoparticles. Meanwhile, the solar-thermal conversion during the evaporation process was analyzed using experimental data and the mechanism of evaporation enhancement of hybrid nanofluids was proposed. This study paves a new way for the use of hybrid nanofluids in the solar steam generation technique.