Large-span ultrahigh roof floor support plate reinforcing device

The utility model discloses a large-span ultrahigh roof floor support plate reinforcing device which comprises a floor support plate, a plurality of X-shaped supports are arranged on the upper end face of the floor support plate, the same supporting frame is fixedly connected between every two X-shaped supports, the same channel steel is fixedly connected to every two supporting frames, and the X-shaped supports are fixedly connected with the channel steel. A plurality of square steel pipes are arranged on the lower end face of the floor support plate and connected with the channel steel through steel wire ropes, the two ends of each steel wire rope are fixed through U-shaped clamps, through holes are formed in the lower end face of the channel steel in a penetrating mode, the steel wire ropes penetrate through the through holes and are in sliding connection with the through holes, and PVC sleeves are arranged on the outer side walls of the steel wire ropes in a sleeving mode. The steel wire rope penetrates t