Screw fastener for anti-seismic support hanger

The screw fastener comprises channel steel, a fastening screw, a side supporting rod and a long screw, the fastening screw is movably connected into a cushion block through hole in a clamped mode, and an anti-disengaging piece is fixedly connected to the position, corresponding to the interior of the cushion block through hole, of the bottom of the fastening screw in a welded mode. According to the long screw fastening device, the fastening spring, the fastening screw rod and the cushion block are matched, so that threads on the surface of the long screw rod are protected through an anti-skid pad at the bottom of the cushion block in the long screw rod fastening process; the cushion block is always pressed on the surface of the long screw rod through the elastic force of the fastening spring to prevent loosening, meanwhile, force is evenly applied to the long screw rod through the side supporting rods and the side supporting springs on the two sides, when the long screw rod deviates, the side supporting sprin