Abstract: As one kind of innovative marine structure,there still not exist public recognized stability analysis theory and practical method for the deep-buried large diameter steel cylinder yet,which seriously blocked the popularization and application of large diameter steel cylinder structure in practical engineering implementation. In order to further improve the theoretical basis of the new structure,this paper carried out three-dimensional elastic-plastic modeling analysis of deep-buried large diameter steel cylinder which is used as wall structure of artificial island in the project of Hong Kong-Zhuhai-Macao Bridge based on PLAXIS 3-D software. The research results show that the horizontal deformation is relatively enlarged,but the overall stability can be greatly improved when the large diameter steel cylinder structure is deeply buried in soft clay foundation as the artificial island wall,.Combining the numerical simulation results and the theoretical plane strain analysis method provided by OCDI standard,a reliable shear and sliding stability calculation method is finally summarized with one set of quantitative evaluation criteria by verifying the measured data of deep-buried large diameter steel cylinder in the practical engineering of the east-west island of Hong Kong-Zhuhai-Macao Bridge. The research results also provode principle suggestions of the applicability of steel cylinder structure to port engineering,which can provide theoretical basis and Engineering reference for the design and optimization of similar constructions.