Abstract: By means of structural innovation, a new type of bamboo scrimber filled steel tube was formed by composite materials of bamboo scrimber and steel tube. Axial compression tests were carried out on 24 cylindrical specimens of the new type of bamboo scrimber filled steel tube to study the effect of steel tube thickness and loading mode (full section and core loading) on its axial compression performance. The test results show that the external steel tube can effectively improve the structural bearing capacity and deformation capacity, and the main failure mode of the bamboo scrimber filled steel tube is shear failure. The peak stress and peak strain of the structure are positively correlated with the steel tube thickness. As the steel tube thickness increases, the maximum increase in peak stress of the specimens reaches 22.4%, while the maximum increase in peak strain is 6.1%. The core loading specimens exhibit better load bearing potential and deformation capacity than the full section loading specimens. Based on the different curves of full section loading and core loading, and considering the steel tube confinement factor, the prediction models of ultimate stress, ultimate strain, peak stress and peak strain of the new type of bamboo scrimber filled steel tube under different loading modes are proposed, and the error of the stress calculation model is less than 10%. Finally, the stress-strain full curve model is proposed, and the stress-strain variation of the new bamboo scrimber filled steel tube under different loading modes is predicted.