A novel ionic liquid type saponification processing based on quaternary phosphonium type bifunctional IL was developed for yttrium separation from ion-adsorbed rare earth deposit.The extractabilities of ([trihexyl(tetradecyl)phosphonium][sec-octylphenoxy acetate] ([P6,6,6,14][SOPAA]) were pronouncedly higher than those of sec-octylphenoxy acetic acid (HSOPAA),a mixture of HSOPAA and [P6,6,6,14]Cl for rare earth elements (REEs).The ion association extraction mechanism contributed to avoiding the numerous saponification procedures using alkali and resulting in saponification wastewater.After 13 stages of extraction and 6 stages of scrubbing sections,the Y(Ⅲ) was successfully separated from industrial heavy RREs feed,the purity of Y(Ⅲ) in raffinate was approximately to be 98.9％.Stripping by distilled water was effectively achieved for REEs,which contributed to the decreased consumption of acid to a considerable extent.