The adsorption and decolorization of water-soluble azo dye(Eriochrome Black T) was investigated based on eggshell membrane. The effect of adsorption time, pH value, temperature as well as the dosage of eggshell membrane on the decolorization of Eriochrome Black T was studied. It is indicated from the experimental results that the azo-dye adsorption with eggshell membrane should be carried out in acidic solution. At the optimum conditions, 95% of Eriochrome Black T could be removed. In this study, the dumped eggshell membrane can be utilized to solve the pollution problem of dye wastewater, which will offer us a new way for utilization of eggshell membrane and treatment of wastewater.