and or pharmaceutic adjuvant the pharmaceutical effective ingredient is iron based montmorillonite fe montmorillonite which is 20 u02dc 100 by weight in the medicine the iron ion is 3 0 u02dc 12 0 by weight in the iron based montmorillonite fe montmorillonite the iron based montmorillonite fe montmorillonite is obtained by soaking or eluting the medicinal montmorillonite by water soluble iron salt solution in which the water soluble iron salt solution is ferrous gluconate ferrous succinate ferrous lactate ferrous fumarate or ferrous sulfat solution and the medicinal montmorillonite is selected from calcium based montmorillonite ca montmorillonite sodium based montmorillonite na montmorillonite or magnesium based montmorillonite mg montmorillonite medicinal montmorillonite is conventional raw material in the field which can be commercially purchased according to the present invention preferred the iron based montmorillonite fe montmorillonite is 50 u02dc 100 by weight in the medicine according to the present invention preferred the iron ion is 5 0 u02dc 9 0 by weight in the iron based montmorillonite fe montmorillonite according to the present invention preferred the concentration of the water soluble iron salt solution is 5 u02dc 15 by weight a preparation method of the iron based montmorillonite medicine for treating hyperphosphatemia and iron deficiency anaemia wherein the step comprises 1 adding pharmaceutical montmorillonite into deionized water acidizing by treating with hydrochloric acid adjusting the ph value to.