Abstract: To investigate the dynamic response of GFRP tube concrete-encased steel (GTCES) cantilever members under low-velocity impact loadings, numerical models were established by the base of the finite element method. The combination behavior, failure modes, and the internal force evolution of members were analyzed. The analysis results indicate that the GFRP tube, the steel and, the concrete form an efficient synergistic mechanism, with the combination effect significantly enhancing the overall impact resistance and energy dissipation capacity of the members. The impact location is a key factor governing the failure mode, as the impact location moves from the fixed end towards the mid-span, the failure mode transitions from shearing failure to flexural failure. The internal force analysis reveals that the fixed-end section is the critical governing section, where the inertial effect exhibits an alternating role in resisting and amplifying the impact load during the impact process.