The invention relates to a sliding open-closed insulator shielding cover, which comprises a body part and a window shielding part, wherein the body part is used for covering an insulator, the body part comprises a top wall and a side wall extending downwards from the top wall, the side wall is provided with a first opening which serves as a window for operating the insulator, and the first openingruns through the side wall in the axial direction of the body part; the window shielding part is installed on the body part in a sliding manner and used for shielding or at least partially exposing the first opening; and the window shielding part and the body part are configured with an anti-falling mechanism therebetween which is used for preventing the window shielding part from falling off dueto gravity. The insulator shielding cover can provide an operation space for operators conveniently and flexibly, can ensure the integrity of insulation shielding, is further conducive to reducing the workload of the operators and also can preventing the window shielding part from falling off at the same time, thereby improving the operation efficiency and the safety.