The invention provides a movable multifunctional external grounding device, which comprises a grounding panel, a grounding pin, a lead screw, a nut, an upper ferrule and a lower ferrule, wherein the top of the grounding pin is fixed on the lead screw; a pedal rod is arranged on the lead screw; the nut is sleeved at the periphery of the lead screw, forms a pair of lead screw nut mechanism with the lead screw and is fixed on the grounding panel; the nut is fixed on the grounding panel through the upper ferrule and the lower ferrule; a water inlet pipeline is arranged on the lead screw; the tail end of the water inlet pipeline is provided with a drainage groove; and the top of the lead screw is provided with an inner hexagon spanner. The movable multifunctional external grounding device is suitable for assembly of substations and output line iron towers and is mainly used for providing shell grounding measures of large equipment with an external power supply and temporary grounding measures in line construction. The device is mainly used for preventing thunderstorm and thunder from damaging the shells of tools and harming personal safety of workers, the thunder can be drained reliably under the ground during raining and lightning, and the workers and the equipment are safe in operation and are protected.