Due to large use of the composite pre-flat slabs “two layers slabs” especially manifested in pre-cast system slabs such as frequently used in bridge dicks, large thickness slabs casted on two layers or change usage of existing structure. Thus, it’s very crucial required to study the behavior of pre-flat slabs in resistance of punching shear forces. Thus, the research presented herein addresses the punching strength as well as the deformation capacity of pre-flat slabs. Thereby, the focus is set on the analysis of the maximum increase in strength and deformation capacity due to punching shear reinforcement.An experimental investigation of twenty slab specimens was conducted to study punching behavior of pre- flat slabs. Specimens classified into sixteen slabs casted as two layers and four control slabs casted as one-layer slab. Specimens have same dimension: “L, B, t“ which are the length of 1100 mm, width 1100 mm, with overall thickness 120 mm, since the pre-flat slabs layers of 60 mm thickness, all columns dimensions “A , B” which are the length of 150 mm, width 150 mm and main reinforcement 4 ɸ16 with shear reinforcement stirrups of ɸ10@50 mm.Therefore, the principal aim is the analysis of pre-flat slabs with different capacities of punching shear reinforcement, throughout an experimental and numerical investigation of pre-flat slabs. Another principal objective was the development of an numerical model that enables accurate predictions of the punching strength and the deformation capacity of pre- flat slabs.