In view of a simplified calculation of the project, the concrete floor slabs and the lower to be vierendeel steel structure beams are simplified to the steel structure beam by using the stiffness equivalent principle, followed by an analysis of the static characteristics of hexagonal honeycomb vierendeel sandwich plate floors and stiffness equivalent steel structure floor under vertical loading with the finite element method adopted. Based on a comparative analysis, the vertical deflection of different concrete floor width has been studied, with a calculation of the effective width of concrete floor of steel-concrete composite structure, as well as an analysis of the relationship between the effective structural width of concrete slabs and the thickness of concrete slab and steel-concrete composite structure. The results show that the flexural stiffness of the hexagonal honeycomb vierendeel sandwich slab floor structure increases positively with the height of the shear key, while the effective width of the upper flange concrete slab decreases with the increase of the slenderness ratio of the shear key; meanwhile, the effective structural width of concrete slab increases positively with that of slab thickness, which shows an approximately linear growth trend.