An innovative composite structure, named concrete-filled RPC tube (CFRT), was presented in the paper. In this system, high-strength stirrups are arranged in prefabricated reactive powder concrete (RPC) tube, and concrete is then casted into RPC tube. Total fifteen large-scale columns were designed and conducted for axial compression test, including nine CFRT specimens, three high-strength stirrup confined concrete (HSCC) specimens and three hollow RPC tubes. Composite action between the RPC tube and internal concrete as well as the spiral stirrup spacing was considered as the main factors in tests. The results show that only slightly cracking without any spalling occurs at the RPC tube of CFRT column when axial load approaches its peak value. Meanwhile, the axial load-carrying capacity of CFRT column is higher than the sum of that of hollow RPC tube and internal concrete, indicating this composite system realizes the superposition effect. The compressive properties of CFRT columns are also improved with the decrease of spacing of stirrups. Moreover, based on Mander model and the corresponding simplifications, contribution ratio of RPC tube for load-carrying capacity of CFRT columns was quantified, and its value increased from 0.22 to 0.26 with the increasing stirrup ratio. Furthermore, a calculation method for load-carrying capacity of CFRT was proposed.