Ten kinds of 2-[(indol-3-yl)-arylmethyl]-malononitrile derivatives (β-indole derivatives) were synthesized through one pot three-component reactions of indole with aromatic aldehydes and malononitrile in the presence of the deep eutectic solvent (DES) choline chloride/urea. The yields ranged from 66%～94% under mild conditions. Furthermore, the relationship between reaction speed and substituent groups was described, the catalytic mechanism for the reaction catalyzed by choline chloride/urea was proposed. The catalyst could be recovered five times conveniently and reused efficiently. All the compounds synthesized were confirmed by 1H NMR、13C NMR analysis.