Abstract: The impact-resistant performance of steel-reinforced concrete beams with a rigid-flexible composite structure was ana-lyzed based on our earlier research outcomes. The focus was to disscuss the influence of constraint forms on the crashworthy perform-ance of reinforced concrete beams with composite laminates. In the process of numerical simulation, the observed beam with four dif-ferent measures incluing the unprotected, the rigid protective, the flexible protective and the proposed one was considered separately. Meanwhile, three considered constraint forms of the beam ends were as follows:fixed at both ends; hingled at both ends; fixed at one end and hingled at the other end. Protective effects of the different measures were compared and analyzed by observing the strain, the displacement, the acceleration and the impact force of the target beam. Numerical results show that, under the same impact conditions the composite system can obtain the optimal protective effect, but constraint forms may have significant impact on suppression of the dynamic response of the beam. Especially, for the beam fixed at both ends the best protective effect may be obtained.