This invention discloses a prefabricated steel-concrete composite beam floor structure, including frame columns, steel main beams, and steel secondary beams. Floor slabs are laid on the steel main beams and secondary beams. Connecting plates are vertically installed on the web of the steel main beams. One end of the
floor slab is wrapped with angle steel. The floor slabs do not contact the frame columns. In this invention, the first
floor slab is connected to the steel main beam by a first bolt, achieving a combined effect between the steel main beam and the first
floor slab, improving the bending resistance and stiffness of the steel main beam. The second and third floor slabs are connected to the steel secondary beams by
spot welding, ensuring that the floor slabs will not collapse under seismic loads. The third floor slab has no rigid connection to the steel main beams, allowing relative sliding between them after an earthquake, thus preventing damage to the slab. Furthermore, a gap is left between the third floor slab and the frame columns to ensure that the deformation of the frame columns under seismic loads does not collide with the floor slab, maintaining the integrity of the floor slab.