The invention discloses a tiled display system and a power-supply method of the same. A power line is drawn forth from a power supply end. The power line comprises a main line and branches, wherein the main line is arranged among display units, and each branch is connected with a display unit. Compared with traditional power supply mode with parallel distributed power supply cables, the cables being used are reduced greatly by the tiled display system and the power-supply method of the same. Besides, compared with the traditional power supply mode with cascading distributed power supply cables, power-supply reliability can be guaranteed by the tiled display system and the power-supply method of the same, and the phenomenon that other display units can not supply electricity caused by the breakdown of one display unit does not occur.