In order to improve the low-temperature desulfurization and denitrification performance of activated carbon, the ultrasound-assisted incipient-wetness impregnation method is used to prepare V₂O₅/AC、CeO₂/AC、Fe-Ce/AC、Mn-Ce/AC，4 kinds of modified activated carbon loaded with transition metal oxides, and the physical and chemical properties of various activated carbon materials are explored by such characterization methods as BET、XRD、FT-IR and NH₃-TPD, and the low-temperature desulfurization and denitrification performance of modified activated carbon in simulated flue gas of different components is studied. The experimental results show that, under the condition without ammonia, 10% H₂O in the flue gas can promote the adsorption effect of AC, V₂O₅/AC, CeO₂/AC, Fe-Ce/AC and Mn-Ce/AC, among them, Mn-Ce/AC has the largest adsorption capacity of NO and SO₂, 5.4 and 10.2 mg/g, respectively; In the presence of ammonia, Fe-Ce/AC shows the best NO catalytic performance (48.2%) and large SO₂ adsorption capacity (13.2 mg/g).