To investigate the influence of critical parameters on the progressive collapse resistance of reinforced concrete (RC)-flat plates, a set of finite-element modeling techniques was established. The modeling of bond-slip behavior between concrete and rebars was especially highlighted, which was found to have a significant impact on the performance of flat plates. Employing the modeling strategy, our previously tested 2×2-bay flat plate substructure (S-1) and a similar specimen (ND) in the literature were simulated for model validation. Key structural behaviors, including tensile membrane and suspension actions in the large deformation stage, could be accurately replicated. Further, the validated S-1 model was used to conduct a series of parametric studies in which the influence of concrete strength, slab thickness, and reinforcement ratio on the collapse performance was examined. The results indicated that the concrete strength and the slab thickness only affected the slab flexural capacity with no impact on the load-carrying capacity after the initial flexural/shear failure. Moreover, the load-carrying capacity due to tensile membrane action was primarily governed by the reinforcement ratio. Further examination on the lateral stiffness suggested a lower bound ultimate flexural strength enhancement of 17%, due to the compressive membrane action, can be obtained.