A sliding-contact power supply system and a three-dimensional circulating garage having the same are provided. The sliding-contact power supply system includes: a plurality of sub-sliding wires, each of the plurality of sub-sliding wires being adapted to be electrically connected to an outside power supply; a plurality of insulation segmentation elements, each of the plurality of insulation segmentation elements being connected between two sub-sliding wires; and a plurality of current collectors, each of the plurality of current collectors being electrically connected to the sub-sliding wire; wherein the plurality of sub-sliding wires and the plurality of insulation segmentation elements form a sliding wire guide rail having a ring shape, and each current collector is slidably disposed on the sliding wire guide rail.