The utility model relates to an appurtenance is used in the electric power field, in particular to a shield cover for covering distribution lines cross arm, the rain cover comprises a cover body, the cover body is including setting up in the first body and the second body of wire pole both sides respectively, first body and second body inboard all be provided with with cross arm complex supporting mechanism, last being provided with of first body is used for connecting the coupling mechanism of second body through setting up the first body and the cooperation of second body in the wire pole both sides respectively, shields the cross arm of wire pole both sides simultaneously, between first body and second body and the cross arm contact more steady, difficultly fall from the cross arm, obscure effect is better, has solved current a shield cover for covering distribution lines cross arm and has easily fallen from the cross arm, leads to the obscure effect inefficacy, causes the technical problem of potential safety hazard for operator person.