In order to improve the dynamic bending properties of engineering protective structures, the work aims to propose a thin-walled square tube structure with foam concrete as the core layer. The quasi-static and dynamic low-speed impact three-point bending experiments were carried out to study the bending behavior of the thin-walled square tubes filled with different densities of foam concrete. The effects of tube wall thickness, core layer length and impact velocity on the bending properties of the filled structure were analyzed by numerical simulation, and the interaction and co-deformation mechanism between the core layer and the tube wall were discussed. Compared with empty tube structure, the average crushing load of foam concrete-filled tube under quasi-static bending and dynamic bending increased by 88.26% and 80.04%, respectively. The bending properties of filled tube structures under quasi-static conditions are determined by local buckling and global bending, while the bending properties under dynamic conditions are dominated by local collapsing deformation.