The invention relates to electric tightening equipment for an overhead transmission line wire, and belongs to the field of electrical auxiliary tools. The equipment comprises a telescopic tightening mechanism, a pressing device, a pole and tower clamping base and a controller; the telescopic tightening mechanism comprises a first motor, and a guide rod and a rotating screw which are arranged sideby side, and the motor drives the rotating screw to rotate positively and negatively; the pressing device comprises a driving mechanism and two oppositely arranged pressing arc rings, the driving mechanism comprises a mounting base and a second motor and a driving screw which are arranged on the mounting base, and the pressing arc rings penetrate through a plus thread section and a left-hand thread section respectively; the mounting base is in threaded connection with the rotating screw and movably sleeves the guide rod, the first motor and the second motor are electrically connected with thecontroller, and the pole and tower clamping base can be detachably connected with a tower bar arranged on a pole and tower. The controller can control the two pressing arc rings to clamp or loosen thewire, and can control the pressing device to move along the guide rod to tighten the wire, and the work efficiency of tightening the wire is effectively improved, and the wire tightening time is shortened.