The utility model provides a strain insulator string with a self-adaptive wire length. The strain insulator string comprises a strain clamp, a drainage plate, a drainage clamp, a connecting device, ahorizontal adjusting device, a jumper wire downlead clamp and a grading ring. The connecting device is used for hanging a wire to a strain clamp or a tower. The horizontal adjusting device comprises aplurality of T-shaped connecting pieces and a fixed connecting assembly used for connecting the T-shaped connecting pieces in series. The jumper wire downlead clamp comprises a downlead assembly anda jumper wire fixing assembly. The utility model relates to a strain insulator string with a self-adaptive wire length. The horizontal distance of the wire can be adjusted by utilizing the horizontaladjusting device connected with the strain clamp through the connecting device, the adjusting range is large, the precision required for measuring the length of the wire is low, and the problem that the adjusting distance does not meet the jumper distance requirement when the drainage plate slides on the sleeve of the strain clamp is solved.