The present invention relates to a high-voltage wire deicing device and a working method, pertaining to the technical field of power maintenance equipment. The device includes: a frame; an opening is arranged on one side of the frame and used for placing wires into the frame; a roller is arranged in the frame, the middle surface of the roller is concave relative to both ends of the roller, so that the roller can be put on a wire to roll and drive the device to move while remaining stable; and two positions, at both sides of the roller, on the frame are both provided with arc hoops, wherein each arc hoop is linked with the frame via a cylinder, and one side of the arc hoop is a blade edge. The working method of the device comprises the steps of placing the wire under the roller inside the frame from the opening, clamping the wire via the arc hoops by controlling the cylinders, moving the device and carrying out deicing operation by using the blade edges of the arc hoops. The high-voltage wire deicing device has the advantages of operation easiness, good effect for deicing, high adaptability of different high-voltage wire conditions, convenience for carrying and on-site installation, saving of manpower and material cost and reducing of the probability of accidental injuries to an operator.