The invention discloses an insulating overhead ground wire based power taking apparatus. The power taking apparatus comprises an auto-transformer, a filter, an electric air valve, an air pressure adjusting valve, a pneumatic motor and a generator, wherein the auto-transformer is connected with one section of a wire for obtaining a first current, and used for performing voltage transformation processing on the first current to obtain a second current; the filter is connected with the auto-transformer and used for filtering the second current to obtain a third current; the electric air valve is connected with the filter and used for generating first air flow based on the third current; the air pressure adjusting valve is connected with the electric air valve and used for performing voltage stabilization based on the first air flow and then outputting steady second air flow; the pneumatic motor is connected with the air pressure adjusting valve and the pneumatic motor rotates based on the second air flow; and the generator is connected with the pneumatic motor and generates current based on the rotation of the pneumatic motor. Due to the induction current-mechanical energy-current conversion of the insulating overhead ground wire, the problem that unstable current is caused by the changes of the induction current along with changes of transmission loads and external environments of power transmission lines due to the reason that the ratio of transformation of the auto-transformer cannot be high is solved.