On the basis of an offshore infrastructure project,the fatigue damage characteristics of a large-diameter steel cylinder structure ultra-deep into foundation soil are analyzed under the vibration force during the sinking construction stage and the wave load after installation.The performance test is carried out through continuous long time vibration force input during the sinking of the test steel cylinder,and the mechanical performance of the structure-equipment system under extreme conditions is tested and verified.The E2 fatigue curve and parameter value obtaining method are presented,and the fatigue analysis results are in good agreement with the actual test.An intermittent continuous vibration force input method is proposed together with the achievement of accurate vibration input control based on force feedback,which can effectively reduce the total vibration time and fatigue damage,and make the fatigue safety of the structure reach nearly 2.0 during vibration sinking construction.According to the test data obtained from physical models under regular and irregular wave conditions,the fatigue damage factor of the steel cylinder caused by sea wave load is less than 0.1,and the irregular wave is less than the regular wave,which accounts for a relatively small proportion in the total damage factor.