The invention relates to a special ground conducting wire hydraulic compression connector for a transmission line, which comprising a hydraulic plier, a left fixture, a right fixture, a left supporting-holding rod, a right supporting-holding rod and a channel steel guide rail, wherein the hydraulic plier is mounted in the middle of the channel steel guide rail in a positioning manner through a positioning base; the left fixture and the right fixture are symmetrically arranged on the left side and the right side of the hydraulic plier, and operate in a sliding manner respectively through a left tackle and a right tackle both sliding on the channel steel guide rail; mounting holes respectively manufactured by the left fixture, the hydraulic plier and the right fixture are on the same axis; the left supporting-holding rod and the right supporting-holding rod are hinged to the left tackle and the right tackle respectively in a mirror symmetry manner. According to the invention, the special ground conducting wire hydraulic compression connector is advanced in construction and simple to operate, can be suitable for the application of various compression connection tubes after a horizontal mid-partition limiting aluminium pipe is adopted, has high precision for horizontally compressing and connecting butted steel connecting pipes and connecting aluminium pipes, can support and hold aluminium conducting wires per se, automatically completes the straightening of ground conducting wires, completely avoids various problems existing in the manual compression and connection, and has the advantages that the compressing connection is reliable, the precision is high and the cost is low.