Abstract: In view of the deficiency of the existing research on the energy absorption characteristics of composite multi-cell structures, a kind of multicellular filling structure (MFS) was proposed, which was filled by some single small-size CFRP tubes (SCT) into large-size CFRP tubes. The quasi-static compression tests of SCT and MFS were carried out, which included full stroke compression and multi-staged compression, then the failure mode and energy absorption characteristics were analyzed. The results show that the failure mode of the outermost CFRP tube of MFS is similar to SCTs, and there is no obvious difference between full stroke compression and multi-staged compression, but the radial deformation of the outermost tube is obvious due to the compression of the inner tube and debris. Compared with the full stroke compression process, the total energy absorption of SCT and MFS is more when they are multi-staged compressed. In this study, the maximum specific energy absorption (SEA) of SCT is 86.0 J/g and the minimum SEA is 59.3 J/g. While, due to the low SEA of the outermost tube of filled structures, the SEA of the MFS is between 69.8 J/g and 75.9 J/g, which is less than the maximum SEA of SCT. The SEA of the MFS is higher than that of SCT with appropriate external constraint and internal carbon tube number by further research.