Abstract: To systematically investigate the mechanical behaviors and failure mechanisms of flange joints in steel corrugated plate-fabricform concrete composite structures, this study combines full-scale bending tests with numerical simulations. The effects of corrugated plate thickness, flange plate thickness, concrete strength, rib thickness,and axial force on the bending performance of three types of component joints were evaluated. The results show that compared with the pure steel corrugated plate structure, the composite structure with fabricform concrete and the ribbed composite structure exhibit significantly improved bearing capacity, increasing by 63.2% and 128.6%, respectively. When the thickness of the steel corrugated plate increases from 5 mm to 7 mm, the average deflection decreases by 22.4%; further increasing the thickness to 9 mm reduces the average deflection by 11.4%, indicating a significant enhancement in flange joint stiffness. When the flange plate thickness increases by 5 mm from 5 mm and 10 mm, the average deflection is reduced by 31.4% and 28.5%, respectively, demonstrating improved deformation resistance. When the rib thickness increases from 5 mm to 10 mm and then to 15 mm, the average vertical displacement at the mid-span decreases by 37.8%, 30.2%, and 12.2%, respectively. For thinner ribs, the improvement in bending performance is more pronounced. Considering bearing capacity, economic efficiency, and construction feasibility, it is recommended that the steel corrugated plate thickness be set between 7～9 mm, the flange plate thick? ness between 10~15 mm, and the rib thickness between 10～15 mm.