Bolt fastening device for power transmission line

The invention relates to an improvement of a drainage plate bolt loading and unloading tool, and in particular relates to a bolt fastening device for a power transmission line. The bolt fastening device comprises an upper clamping part and a lower clamping part, which are oppositely arranged, wherein the upper clamping part is arranged in a transmission case in a rotatable manner; the transmission case is fixedly connected to one side of a power box; a main shaft which is in transmission connection with a hand crank is arranged in the power box through a bearing; a driven gear is fixedly connected to the upper clamping part and is in transmission connection with a driving gear at the upper end of the main shaft; a thread bushing sleeves the lower end of the main shaft; a longitudinally arranged slide chute is arranged at the lower end of the power box; a support arm is arranged in the slide chute in a sliding manner; the lower clamping part is arranged at the outer end of the support arm; and a thread jacket