This paper seeks to address practical experimental techniques on axial compression behaviors of flexible foldable lenticular composite tube (LCT) with ultra length. A testing system was designed and established to determine the axial compression behaviors of ultra-length LCT, and the axial compression stiffness and buckling load of LCT with the length of 6m were measured by this testing system. In order to verify the measurement from the novel experimental method, eigenvalue buckling FEA model of the LCT with the length of 6m was established to predict the axial compression buckling load that have a good agreement with the experimental data. It is shown that the new developed testing system can accurately and expediently determine the axial compression behaviors of ultra-length LCT .