Herein,TBP is selected as a ligand to investigate the extraction and electrochemical behavior,which is coordination compound of uranyl-TBP and [Bmim][NTf2]system in our work. It is found that hexavalent uranium transforms into tetravalent uranium by two steps of single electron reduction. And the reduction potential,pentavelent uranium to tetravalent uranium,exceeds the system's electrochemical window. The electrodeposition is U3( PO3)4,then turns to UP2O7by heating at about 573 K. It indicates that ionic liquids may show bright prospect in electrochemical separation of spent nuclear fuel reprocessing.