Solvent extraction is an economical and effective method for the purification of wet process phosphoric acid（WPA）. WPA extraction proces was carried out using methyl isobutyl ketone（MIBK） as an extractant in a rotating disc column （RDC）.The effect of rotation speed and phase ratio on the extraction rate,the selectivity coefficient of impurities,and phos-phoric acid washing and stripping was studied.The results showed that the optimum extraction ratio（volume ratio of solvent to phosphoric acid） was 4,the stirring speed was 200~400 r/min,and the extraction rate of phosphoric acid was 85%.The stir-ring speed in the washing process was limited to 100 r/min.The appropriate amount of washing acid was 10%~15% of the vol-ume of solvent phase.The removal rates of Fe³⁺ and Mg²⁺ were more than 90%.The removal rate of Al³⁺ was more than 70% and the removal rate of SO₄^2- was 50%~60%.The stirring speed of stripping process was limited to 200 r/min,and the appropriate amount of stripping water was 9%~15% of the volume of solvent phase.MIBK had good removal effect on cations,but poor re-moval effect on anions.After purification by extraction,washing and stripping,the yield of phosphoric acid was 57.8%~70.3%. The content of Fe³⁺ in phosphoric acid could meet the standard of industrial phosphoric acid,but the content of sulfate could not meet the standard,so it needs to be further removed in combination with other methods.