In this study, polyvinyl alcohol-chitosan-cysteine-functionalized graphene oxide (PCCFG) hydrogel was synthesized from L-cysteine-functionalized graphene oxide (CFG), chitosan (CS), and polyvinyl alcohol (PVA). The hydrogel was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and energydispersive X-ray spectroscopy and employed for removing lead ion (Pb 2+ ) and cadmium ion (Cd 2+ ) from aqueous solution. The effects of initial metal ion concentration, hydrogel dose, pH, time, and temperature were studied. The experimental data were well described by a pseudo-second-order kinetic model and Langmuir isotherm with maximum adsorption capacities of 250 and 192 mg g −1 at 25°C for Pb 2+ and Cd 2+ , respectively. The adsorption capacity of the PCCFG hydrogel increased with an increase in temperature. The value of ΔG°was negative, which shows the spontaneity of the reaction (electron exchange or ion exchange) between the metal ion and electron-rich atoms (-N, -S, -O). The positive ΔH°shows that the adsorption reaction consumes energy and the positive ΔS°shows the strong affinity of PCCFG toward the Pb 2+ and Cd 2+ ions. Pb 2+ had better affinity and less spontaneity than Cd 2+ . The results show that the coexistence of Pb 2+ , Cd 2+ , and Cu 2+ in the solution inhibits the adsorption capacity of PCCFG.