The invention provides an insulator shielding cover which comprises a cross arm cover and an insulator cover. The cross arm cover and the insulator cover are made of insulating materials. The cross arm cover is of a strip shape. A clamping groove matched with a cross arm is formed in the cross arm cover. The bottom side and the two opposite wide sides of the cross arm cover are arranged to form an opening communicated with the clamping groove. The insulator cover comprises a main cover body and a secondary cover body. An insulator containing cavity is formed in the main cover body. The wide side of one end of the cross arm cover and the left side face of the main cover body are fixed and integrated, and the clamping groove is communicated with the insulator containing cavity. The bottom face and the right side face of the main cover body are open. The upper side face of the main cover body is provided with a strip-shaped groove opening. The upper side face of the secondary cover body is provided with a strip-shaped groove corresponding to the strip-shaped groove opening. A notch is formed in the portion, on the edge of the secondary cover body, of one end of the strip-shaped groove. The other end of the strip-shaped groove is of a semi-circular shape. The main cover body is inserted into the secondary cover body from the right side face. The insulator shielding cover is simple in structure, light in weight and easy and convenient to operate; the cross arm can be effectively insulated and shielded through one-time operation, the work time is remarkably shortened, the work efficiency is improved, and the operation safety is improved.