The invention relates to an overhead line repair tool. The tool includes a left half pressing block and a right half pressing block; the inner sidewall of the left half pressing block is provided witha left arc-shaped pressure groove along a width direction, and the inner sidewall of the right half pressing block is provided with a right arc-shaped pressure groove along the width direction; and arepair cavity for placing an overhead line can be formed by the left and right arc-shaped pressure grooves after the left and right half pressing blocks are buckled to each other. A working method ofthe tool is also related. The tool is simple and reasonable in structural design, convenient for the repairing on the overhead line, easy to operate, efficient, convenient and labor-saving and time-saving, and has wide application prospects.