Preparation method of SEBS (Styrene-Ethylene-Butylene-Styrene) through catalytic hydrogenation of ionic liquid-ruthenium/rhodium phosphine

The invention discloses a preparation method of SEBS (Styrene-Ethylene-Butylene-Styrene) through catalytic hydrogenation of ionic liquid-ruthenium/rhodium phosphine, which comprises the following steps: preparing a catalyst system by taking ruthenium phosphine or rhodium phosphine as a main catalyst and taking quaternary ammonium salt ionic liquid or pyridinium salt ionic liquid as a fixing agent of the main catalyst and a solvent; then, the catalyst system and SBS are put into an organic solvent phase to be subjected to a catalytic hydrogenation reaction, and after the reaction is completed, a reaction mixture can form obvious two-phase layering, so that the layered catalyst system can be completely separated out through simple decantation treatment; the separated catalyst system can be directly used without further processing, and the repeatedly used catalyst system has high catalytic activity and can be directly used without supplementing a new catalyst system during use. The method is suitable for the fie