The invention discloses a lightning arrester live-line test overvoltage protection special test wire. The lightning arrester live-line test overvoltage protection special test wire comprises a first lead wire clamp, a second lead wire clamp, a protective gap, a leakage current test inlet wire, a leakage current test outlet wire, a fuse, and a lightning arrester leakage current tester. The first lead wire clamp and the second lead wire clamp are connected with the two ends of the protective gap by wire clamp electric streamlines, and the two ends of the protective gap are connected with the current input end of the lightning arrester leakage current tester respectively by the leakage current test inlet wire and the leakage current test outlet wire. Short circuit of a leakage ammeter of a metal oxide lightning arrester is realized by adopting the upper end lead wire clamp of the leakage ammeter and the tail end grounding wire clamp of the leakage ammeter, and then the leakage current of the interval valve disc of the metal oxide lightning arrester basically passes the inner side of the lightning arrester leakage current tester, and then the value of the leakage current is measured accurately. The lightning arrester live-line test overvoltage protection special test wire has advantages of simplicity, reliability, and abilities of facilitating test wiring and guaranteeing safety of electrical testers during operation to the greatest extent.