The invention relates to an electric dust remover. The electric dust remover comprises a cathode hanging rod and a wall penetration sleeve which is arranged outside the cathode hanging rod in a sleeving mode. The portion, located above the wall penetration sleeve, of the cathode hanging rod is fixedly connected with a fastening nut, the lower end face of the fastening nut makes contact with the upper end face of the periphery of an opening of the wall penetration sleeve in a limiting mode, and a gap between the cathode hanging rod and the wall penetration sleeve is sealed. The phenomenon of discharge along dielectric surface of the surfaces of existing supporting porcelain sleeves is avoided by means of the arranged wall penetration sleeve. By changing the position of the fastening nut on the cathode hanging rod, the height position of a cathode frame on an electric field can be adjusted, so that the dust removing efficiency of the electric dust remover is improved.