An absorbable iron-based implantable device, including an iron-based substrate and a hydrophobically-modified high polysaccharide attached to the iron-based substrate. The solubility of the modified high polysaccharide in an organic solvent is increased when hydrophobically modified, this allows great film formation on the iron-based substrate when a coating method such as spraying or dip coating is employed for the preparation of a coating, thus allowing an increased amount of the modified high polysaccharide to be attached to the iron-based substrate. When the absorbable iron-based implantable device is implanted into the body, the degradation of the modified high polysaccharide produces an increased amount of degradation product that reacts with a corrosion product of the iron-based substrate to produce a water-soluble polysaccharide-iron complex, thus reducing the production of an insoluble solid corrosion product.
