Abstract: The sodium alginate (SA)-based filtration membrane is an ideal membrane separation material for wastewater containing Pb(Ⅱ). It is very valuable but lacking to study the effect of adsorption behavior on membrane filtration. The graphene oxide (GO) and urea were added into SA and crosslinked with CaCl₂ solution to prepare GO/SA composite membrane to investigate its adsorption performance for Pb(Ⅱ) in aqueous solution. The effects of Pb(Ⅱ) initial concentration, GO mass fraction, initial pH value, adsorption time, adsorption-desorption times and other conditions on the adsorption effect were investigated by static adsorption experiments. The adsorption kinetics and adsorption thermodynamics analysis were also carried out on the adsorption process. The adsorption mechanism of Pb(Ⅱ) on GO/SA composite membrane was analyzed by FTIR-ATR and XPS. The experimental results show that the adsorption amount of Pb(Ⅱ) is positively correlated with the initial concentration of Pb(Ⅱ), the adsorption effect is optimal at pH=5, and GO mass fraction of 0.3wt% is the optimal ratio; the adsorption process conforms to the pseudo second-order kinetic model; The thermodynamic isotherm adsorption process accords with the Langmuir isotherm adsorption model. At temperature of 318 K, the adsorption capacity of GO/SA composite membrane obtained by the Langmuir model is 320.51 mg·g^-1. The adsorption mechanism of GO/SA alginate composite membrane on Pb(Ⅱ) is mainly physical adsorption.