The invention relates to a lightning arrester shielding device. The lightning arrester shielding device is characterized in that a shielding ring is arranged at one end portion of an operating rod; the shielding ring includes a fixed half ring (2) which is fixed at the end portion of an operating rod and is provided with a hollow cavity, and a movable half ring (3) which is arranged in the fixed half ring (2) and can be ejected out from the hollow cavity or be accommodated in the hollow cavity; a reset spring (12) is arranged in the hollow cavity of the fixed half ring (2); the lower end of the reset spring (12) is fixed to the fixed half ring (2); and the upper end of the reset spring (12) is connected with the movable half ring (3). With the lightning arrester shielding device adopted, a user does not need to climb a ladder. The lightning arrester shielding device can be operated by one person. With a shielding ring adjustment mechanism adopted, the size of the opening of the shielding ring can be adjusted. Thus, operational safety and adaptability can be improved, and the safe, healthy and stable operation of equipment and a power grid can be ensured. A steering head is adopted, and therefore, the adjustment of the direction of the shielding ring can be facilitated. The shielding ring adjustment mechanism is ingenious in design, is reasonable in structure, and is convenient to operate.