The invention discloses a full-tooth driven high-altitude grounding test device which mainly comprises a machine case and a transmission system. The transmission system of the device adopts a gear mechanism and is wide in adopted circumference speed and power range, high in efficiency, stable in transmission ratio, long in service life and high in working reliability. Main parts are standard parts or are simple in structure and easy to manufacture. The gear mechanism is adopted to drive a pliers body to close and can provide enough clamping strength. The self-locking effect is improved, the pliers body is not easily loosened, and meanwhile removal of an oxidation layer and influence of the oxidation layer are also facilitated. A test clamping piece for clamping is machined with a transverse cutting edge and a longitudinal cutting edge, has three freedom degrees and can remove the oxidation layer in a floating mode. In short, the full-tooth driven high-altitude grounding test device is simple in structure, convenient to operate and excellent in efficiency, can be used for directly conducting overhaul wiring operation on a high-altitude device on the ground, and the problem that high-altitude wiring is difficult and high-voltage lead oxidation layer removal effect is poor and accordingly test accuracy is influenced is overcome.