The utility model relates to an extra -high voltage overhead transmission line insulator chain type structure, concretely relates to three become two link fitting and use this link fitting's insulator chain. Three become two link fitting including articulating upper plate and the hypoplastron that links to each other from top to bottom, the interval set up about the upper plate had is used for the connecting hole that links to each other respectively with the trigeminy insulator, and the hypoplastron has the mounting hole that is used for articulated installation suspension clamp that is located the articulated department left and right sides respectively. Change the three stress point of upper plate two stress points of hypoplastron both sides into, simple structure has reduced center height, the on -the -spot installation of being convenient for. The suspension clamp of installation on the hypoplastron can the automatically regulated left and right sides the force balance, the disequilibrium that ice back etc. Causes, the steady safety of assurance serial type can also the automatically regulated tower position discrepancy in elevation be carried out with the wire to wire easy to assemble.