Provided is an ultrahigh voltage power transformation engineering four-split-conductor strain insulator-string. Each suspension string is composed of a U-shackle I, a turnbuckle, a ball eye, an insulator and a socket-clevis eye which are sequentially connected. The bottom ends of the socket-clevis eyes of the two of the suspension strings are connected to a yoke plate. A grading ring is installed on the yoke plate. The ultrahigh voltage power transformation engineering four-split-conductor strain insulator-string has characteristics that the bottom portion of the yoke plate is connected to a hanger which is composed of a left end plate, a right end plate and a support plate fixed between the left end plate and the right end plate. The outer sides of the left end plate and the right end plate are respectively provided with shield rings. The front ends of the left end plate and the right end plate are respectively and sequentially connected to U-shackles II, pull rods, adjusting plates and strain clamps. The rear ends of the left end plate and the right end plate are respectively and sequentially connected to U-shackles III, adjusting plates, parallel clevises, extension plates and strain clamps.