A single-motor window shutter for a large window comprises a shutter box. An upper cover, a left end seat, a right end seat and a lower cover are connected by end screws to form the shutter box, a reel which is respectively rotationally connected with the left end seat and the right end seat is horizontally disposed on the shutter box, a tubular motor is arranged on the reel, a left guide track is vertically arranged at the lower end of the left end seat, a right guide track is vertically disposed at the lower end of the right end seat, two shutter hanging sheets are wound on the reel, a middle end seat is arranged in the middle of the shutter box, a through hole is disposed in the middle of the middle end seat, the reel penetrates through the through hole, and a middle guide track with double tracks is arranged at the lower end of the middle end seat. The single-motor window shutter for the large window has the advantages that production cost is sufficiently reduced while a mechanical performance is guaranteed and wind load resistance and an antitheft safety performance are improved, and failure rate of the electric window shutter is reduced; the problem that a gap is formed when a conventional window shutter is used and two shutter boxes of the conventional window shutter are spliced is avoided owing to the middle end seat, and sealing and heat-insulation performances are fine; and the shutter window is integrated, is more attractive and is installed more simply and easily.