The invention discloses a dirigible chair on an over head line for maintenance of a power transmission line. The dirigible chair comprises a main support and a driving device, wherein at least two rods are arranged on the upper end of the main support; the plurality of rods are arranged at intervals and in parallel with each other, and the body of each rod is upward; each rod body is connected with a roller device which can be opened and closed so that the power transmission line can be separated from the roller devices or passes through the roller devices; and rollers are arranged on the roller device and can roll on the power transmission line when the power transmission line passes through the roller devices. The dirigible chair on an over head line for maintenance of a power transmission line is simple in structure and convenient to use; and by opening the roller frames which can be opened and closed, the dirigible chair on an over head line for maintenance of a power transmission line can step over barriers so that the maintenance efficiency of the power transmission line can be improved and the personal safety of workers can be guaranteed.