The invention discloses an oil gathering line repairing device and method and belongs to the technical field of oil recovery machinery for oil fields. The oil gathering line repairing device comprises a threaded nipple and a plug, wherein the threaded nipple adopts a hollow tubular structure with internal and external threads, and one end of the threaded nipple is fixed in a position, which has the preset length from an oil leakage position, of an oil gathering line; the plug is arranged at the other end of the threaded nipple and provided with an external thread matched with the internal thread of the threaded nipple, the top end of the plug adopts a square structure, and the maximum diameter of the square structure is smaller than the diameter of the plug. The oil gathering line repairing device adopting the structure can effectively solve problems of environmental pollution caused by oil gathering line tapping, low construction efficiency and the like in the prior art.