ALC prefabricated floor support plate and construction method thereof

The invention discloses an ALC prefabricated floor support plate and a construction method thereof, and belongs to the technical field of building construction, a profiled steel sheet is used as a bottom formwork for pouring, the stress performance of the profiled steel sheet is optimized in combination with a steel bar truss, and the profiled steel sheet wraps an ALC plate, so that the ALC plate is not prone to damage in the carrying and mounting process, and the construction efficiency is improved. The waterproof post-pouring groove is arranged to avoid the leakage problem at the joint of the floor slab, the profiled steel sheet loses the bearing capacity when a fire disaster occurs, the steel bar truss can continue to serve as a stress structure to bear the load, and meanwhile, the functionality of the ALC slab can continue to be kept. The proportion of the ALC slab and the concrete slab is adjusted according to different heat preservation and heat insulation requirements to form a prefabricated two-way sl