Floor slab, as main components of structure, has a great influence for progressive collapse. Therefore, in the research of progressive collapse, it is necessary to consider the role of the floor. we use the finite element program of ABAQUS, and simulate the failure of center pillar along long side about the frame structure with two layers. Contrast progressive collapse cases of RC frame structure for considering and not considering floor effect, summed up the floor impact on continuous collapse of RC frame structure. The results show that the floor can greatly improve the resistance and stiffness of the structure, increase structural integrity, and postpone the beam hinge appearing to improve the performance of the structure resisting progressive collapse.