A kind of hydrolysis resistant porous hydrogel was prepared using sodium alginate (SA) as raw material, acrylic acid (AA)、2-acrylamido-2-methylpropane sulfonic acid (AMPS) as the monomers, tetraallylammonium bromide (TAAB) as crosslinker, EDTA as modifying agent. The water absorbency and adsorption performance of Cu2 、Cr3 were determined and the gel adsorption isotherm and adsorption kinetics were studied. The surface morphology of hydrogels were analyzed by FTIR、SEM、AFM. According to the results, the swelling rate of hydrogel could be significantly improved with the addition of SA, and the modified hydrogel had excellent hydrolysis resistance. The water absorption ratio in distilled water at 125℃ could reach 350.4 g/g.Adding the modifier EDTA disodium and increasing the pH value of the solution were conducive to improving the adsorption performance of the hydrogel on Cu2 and Cr3 , with the maximum adsorption capacity of 539.2 and 286.7 mg/g respectively.The adsorption mechanism of the hydrogel on Cu2 was in line with the Langmuir adsorption isotherm, while the adsorption of Cr3 was in line with the Freundlich model. The adsorption process was spontaneous exothermic. When the adsorption temperature increased, the adsorption equilibrium time decreased, and the adsorption capacity decreased slightly.