The invention provides a method for utilizing sludge fermented waste for preparing heavy metal ions absorbent. The method is characterized by comprising the steps that sludge is fermented in an anaerobic mode, the fermented sludge is concentrated to obtain fermented waste, a nutrition conditioning agent is added into the fermented waste, and secondary fermentation is carried out to obtain secondary fermented waste; the obtained secondary fermented waste is concentrated and placed into a closed reactor, a catalyst is added to carry out reaction, and after-treatment is carried out to obtain the heavy metal ions absorbent. The rate of absorbing heavy metal by a carbon material is remarkably increased, and the organic waste can be utilized efficiently in a resource mode.