The invention relates to a cross arm shielding cover, which comprises a body part and a first movable shielding part, wherein the body part is of a hollow cover-shaped structure and used for coveringa cross arm, a first end of the body part is provided with a first opening used for allowing the cross arm to pass through, the body part comprises a top wall and a pair of side walls extending downwards from two sides of the top wall, and the top wall is provided with a first window used for exposing a pin insulator on the cross arm; and the first movable shielding part is movably installed on the body part and used for shielding or at least partially exposing the first window and exposing the pin insulator via the first window. The cross arm shielding cover is enabled to expose the corresponding part of the cross arm for operation without integral moving or disassembling in the normal using process due to the setting of the operation window capable of being opened and closed, the use isvery convenient, and the safety protection performance is also higher.