Multifunctional composite catalyst for carbonyl sulfide hydrolysis under moderate temperature was prepared by impregnation method. The hydrolysis and deoxidization ability of the prepared catalyst was investigated in a fixed bed reactor. It was found that deoxidization ability of the prepared catalyst was raised by the increase of the content of potassium loading catalyst and reaction temperature. And the concentration of H₂S had no effect on deoxidization while COS improved the deoxidization ratio. And deoxidization rates were nearly scaled up with concentration of H₂. The hydrolysis ability was decreased by the decrease of the surface basicity.