The invention discloses a special wire clamp for performing a charged test on a lightning arrester. The special wire clamp comprises a first connecting tube, wherein a second connecting tube is mounted on one side of the middle part of the first connecting tube; the interior of the second connecting tube is communicated with the interior of the first connecting tube; a first conductive wire and a second conductive wire are mounted inside the first connecting tube; a fixing tube is mounted at the upper end of the first connecting tube. The special wire clamp adopts a T-shaped design, the first connecting tube and the second connecting tube are made of an insulating material, and the conductive wires are enwrapped inside the first connecting tube and the second connecting tube; a first magnet and a second magnetic suction chuck of the special wire clamp can be tightly connected with a conductor to be prevented from being separated from the conductor, so that the accuracy of voltage measurement data is improved.