Cyclohexene is a very important organic chemical raw material. Selective hydrogenation of benzene to cyclohexene is the best way to obtain high-yield cyclohexene. For a long time, researchers have been committed to developing a ruthenium-based catalytic reaction system with high selectivity and high yield to produce cyclohexene. However, environmental factors have restricted its large-scale industrial application, so it is necessary to Further research. Green catalysis is one of the hotspots of current research. The trend of developing highly hydrophilic catalysts with less ruthenium loading and no reaction additives is bound to be strengthened in the future development of green chemistry. Therefore, the technology of hydrogenation of benzene to cyclohexene Development is an extremely economically significant and scientifically challenging subject. This article systematically introduces the technological progress of selective hydrogenation of benzene to cyclohexene from the aspects of reaction process technology, development history, reaction system composition and reaction mechanism of ruthenium-based catalysts.