A novel method of highly efficient and selective transfer hydrogenation of azobenzenes to hydrazobenzenes catalyzed by sodium decatungstate (NaDT) has been reported for the first time. The reaction can be smoothly proceeded in the presence of isopropyl alcohol (2-PrOH) and upon 390 nm UV-light irradiation at room temperature. The corresponding 40 kinds of hydrogenated azobenzene can be obtained by selective reduction of either symmetrical or asymmetrical azobenzene in 25-960 min, and the yield can reach more than 98%. It is worth noting that NaDT maintains catalytic activity for 5 consecutive cycles in the reduction of azobenzene to 1,2-diphenylhydrazine, with little change in yield. Additionally, This reaction can be easily applied in gram-scale experiment without any changes in reaction conditions and reaction activity. Moreover, this reaction has the most catalytic effect compared with similar reactions reported recently. Furthermore, the mechanism study shows that 2-PrOH provides hydrogen source for the reaction and realizes the transformation through free radical pathway.