The invention relates to the technical field of adsorbent preparation and in particular relates to a method for preparing an adsorbent of special morphology. The method comprises the following steps:(1) weighing a certain amount of polysaccharides to be dissolved into an aqueous solution of acids, stirring until the polysaccharides are dissolved, and leaving to stand for 1-5 hours; (2) dropping the polysaccharides solution in the step (1) into a mixed solution of sodium hydroxide and ethanol having a certain concentration according to 1-2 drops per 2s while stirring, and leaving to stand for1-12 hours; (3) filtering the mixed solution in the step (2), and washing to be neutral, thereby obtaining the adsorbent of special morphology. The adsorbent prepared by the method disclosed by the invention has the special morphology of core-removed hawthorns, has large specific surface area, and has very ideal treatment effects on wastewater containing heavy metal ions and dyestuffs; the preparation process is simple, and the conditions are mild.