It discloses an iron-based montmorillonite medicine for treating hyperphosphatemia and iron deficiency anaemia, and the preparation method thereof. The medicine comprises effective ingredient iron-based montmorillonite (Fe-montmorillonite) which is obtained by soaking or eluting the medicinal montmorillonite by water soluble iron salt solution. The effective ingredient is added by pharmaceutic adjuvant or not to make medicanent which is given via gastrointestinal tract. The effective ingredient binds the phosphate in the patients digestive tract to form insoluble matter which can be excreted from the body via the digestive tract, therefore the phosphate in the patients with chronic renal failure is reduced and the goal of treating hyperphosphatemia is achieved.
