The utility model discloses a special clamp for a tensile duplex porcelain vase type insulator string on power transmission lines, characterized by comprising clamping mmebers and leading screws, wherein the two clamping members are symmetrically arranged, and the leading screws are symmetrically arranged at both ends of each clamping member, and the corresponding ends of the two leading screws are connected with one clamping mmeber through screw threads and the other corresponding ends of the two leading screws are connected with the other clamping member through screw threads. The special clamp for a tensile duplex porcelain vase type insulator string on power transmission lines is simple in structure, low in cost and easy in mounting, and convenient for stringing a wire; and an L-shaped yoke plate suffers a tension force, but the L-shaped yoke plate is still stable and does not to move up and down and left and right. The special lead screw clamp and the leading screws replace the double-hook stringing device to string a wire, in order not to overturn an entire duplex plate and the insulating string, thereby increasing security coefficient, effectively increasing working efficiency, shortening power failure time, and increasing the economic benefit for enterprises.