The invention discloses a treating agent for jointly removing heavy metal ions in industrial wastewater. Raw materials comprise polystyrene divinylbenzene resin microspheres, ethylenediamine tetraacetic acid, a dithiocarbamate, polyethyleneimine, glutaraldehyde, black wattle tannin, poly(2-acrylamide-2-methylpropanesulfonic acid), maleic anhydride, dialkyl dithiophosphate, polyaspartic acid, 2-amino-3-mercaptopropionylchitosan, polyethyleneimine sodium xanthate, mercaptoacetic acid, dibutyl phthalate, polyepoxysuccinic acid, dioctyl sodium sulfosuccinate, a cross-linking agent and a coupling agent. The treating agent can be used to jointly remove heavy metal ions in industrial wastewater under coexistence ions, is not influenced by ion interference, and can form stable compounds precipitate with most monovalent and bivalent heavy metal ions such as Fe<2+>, Ni<2+>, Pb<2+>, Ag<+>, Zn<2+>, Cd<2+>, Hg<2+>, Ti <+>, Cr<3+> and the like for precipitation, so that the purpose of removing heavymetal ions is achieved. The removal effect can be achieved regardless of the concentrations of the heavy metal ions in wastewater. When a plurality of metal ions coexist, the metal ions can be simultaneously removed. When heavy metal ions exist in a form of complex salt (ethylene diamine tetraacetic acid (EDTA), tetramine and the like), a good removal effect can also be achieved.