An innovative composite structure, named seawater and sea sand concrete（SWSSC） filled reactive powder concrete（RPC） tube（SFRPCT），was presented in the paper. In the hybrid system, carbon fiber reinforced polymer（CFRP） hoops are arranged in prefabricated RPC tube and then SWSSC is cast in tube. From the material durability point of view, SFRPCT has excellent corrosion resistance and it can be potentially applied in marine construction. A total of 15 large-scale columns were conducted under axial compression test, including 12 SFRPCT specimens and 3 CFRP hoops confined SWSSC（FRPHSC） specimens. Composite effect between RPC tube and internal SWSSC and influence of mechanical properties from lateral confinement level were investigated in test. The results showed that only slight crack on RPC tube of SFRPCT column occurred without any spalling when axial load approached its peak value. Compressive strength and ductility of the SFRPCT columns were significantly higher than those of the corresponding FRPHSC specimen and increased with the increase of the volumetric hoop ratio in RPC tube. Therefore, SFRPCT hybrid system effectively combined the super-high strength of RPC and confinement effect by CFRP hoops. Based on existing test data and model, a calculation method for carrying capacity of SFRPCT was proposed. Contribution ratio of RPC tube for carrying capacity of SFRPCT columns was quantified and its value varied from 0.39 to 0.42.