The invention discloses a gel adsorber used for wastewater treatment. The gel adsorber comprises the following raw materials in parts by weight: 20-40 parts of tetraethyl orthosilicate, 15-25 parts of zirconium oxychloride octahydrate, 50-80 parts of ethylenediamine diaceturate and 70-100 parts of methylbenzene. The gel adsorber is obtained by putting tetraethyl orthosilicate in methylbenzene, heating the materials to 65-75 DEG C, stirring the materials for 5-10 minutes, then raising the temperature to 120-140 DEG, then adding zirconium oxychloride octahydrate and ethylenediamine diaceturate, stirring the materials for 0.5-2 hours and then putting the product in a drying oven at 90-100 DEG C to be dried. The gel adsorber can effectively adsorb Cu<2+>, Cd<2+> and Pb<2+>, has strong heavy metal ion adsorption and exchange capability and has high adsorption capacity, strong adsorption capability and high efficiency when being applied to treatment of heavy metal ions in wastewater. The treated wastewater reaches the national discharge standards.