The invention relates to a catalyst for preparing cyclohexene through selective hydrogenation of benzene and a preparation method and a use method of the catalyst. The catalyst consists of nano Ru, hexagon zinc sulfate composite salt, zinc sulfate and water, wherein the mass ratio of nano Ru to hexagon zinc sulfate composite salt to zinc sulfate to water is 1:(0.1-10):(1-50):(10-300). The catalystprovided by the invention is simple to prepare, the conversion rate of benzene and the selectivity and the yield of cyclohexene can be effectively increased, and the catalysis performance of the catalyst is remarkably better than that of a conventional industrial catalyst.