The large-diameter steel cylinders are applied to harbor and sea-crossing engineering.But there is still a lack of grasp of the deformation characteristics of the-large diameter steel cylinders.Based on the measured data of the East Artificial Island of Hong Kong-Zhuhai-Macau bridge,we carry out the study on it.The result reveals that with the soil consolidating in the cylinder,the deformation characteristics of the steel cylinder is similar to that of the gravity structure.