Abstract: An underwater oil and gas production system is proposed to adopt large-diameter thin-walled steel cylinder as a protective facility. When the jackup drilling ship is operating, the insertion and removal of spudcans will cause a wide range of soil squeezing. When the insertion and removal position of spudcans is close to the underwater protection facilities, the stability of the underwater protection facilities and their foundation will be seriously affected. For this reason, the centrifuge model tests are carried out to study the influences of different depths and spacings of a spudcan in clay on the steel cylinder of the protective facilities. The results show that the wall strain, top deformation and wall earth pressure of steel cylinder decrease with the increase of the cylinder-spudcan distance, and increase with the increase of the spudcan depth, and develop synchronously with the pressure resistance of the spudcan. When the cylinder-spudcan distance is less than 0.9 times the diameter of the spudcan, the wall of the steel cylinder will yield. The top deformation of the cylinder is mainly the horizontal displacement developed into the cylinder. The increment of the earth pressure on the cylinder wall is 0.6 times that of static earth pressure. The influence range of the spudcan on the steel cylinder exceeds 1.3 times the diameter of the spudcan.