Activated carbon (AC) was modified with microwave irradiation heating at 600, 700 and 800 °C respectively. The physicochemical properties of the activated carbon were characterized by using Boehm titration, Fourier transformed infrared spectroscopy and Specific surface area and pore size analyzer. Fixed-bed adsorption experiments were conducted by using 1,2-dichloroethane as the adsorbate. The results show that, after microwave modification, the surface acidic functional groups of activated carbon decrease and the surface basic functional groups increase with the increase of temperature. The specific surface area and total pore volume of activated carbon decrease, while the micropore specific surface area increases. The order of the adsorption capacity for 1,2-dichloroethane is AC-800 > AC-700 > AC-600 > AC-0.The results of the grey relativity analysis show that the physical properties of the modified activated carbon have a larger effect on the adsorption capacity than the surface functional groups. The fitting results of D-R model and kinetics equation illustrate that it is a physical adsorption process for activated carbon.