At present, the malodorous gases as a main environmental problem derived from livestock farm have been taken seriously. Meanwhile, it is urgent to eliminate the odor pollution. The combination of high-pressure hydrothermal method and impregnation CuSO4 method is used to modify the raw activated carbon. The adsorption performance of H2S derived from livestock farm on modified activated carbon (MAC) has been investigated at different conditions in self-made fixed bed. The results show that, lower temperature makes for H2S physical adsorption on MAC, but it against chemical adsorption on it. The ability of H2S chemical adsorption improves with the increasing temperature, at the same time, the ability of H2S physical adsorption weakens. The optimal adsorption temperature is 80℃, which balances the chemical adsorption and physical adsorption on MAC. The gas flow rate goes up with the space velocity increases. The time that H2S stays in fixed bed is shortened and the H2S adsorption capacity on MAC declines as well. The H2S removal efficiency and breakthrough time on MAC decreases along with the increase of the H2S concentration in the range of 150-850 mg/m 3. Moreover, the physical and chemical structures of raw activated carbon and MAC have been characterized by FTIR, TPD, Boehm methods. The results demonstrate that the pore structure of the activated carbon, the types of carbon functional groups and the surface basic of activated carbon have significant influence on the H2S adsorption ability on activated carbon.