With the development of oil development to deep-water field, the number of oil exploitation methods has increased, and different exploitation methods have also brought different stress analysis under different constraints. In this paper, according to the installation process of the new oil exploitation mode, the corresponding three-dimensional simulation model is established, combined with the extreme wave and current velocity that occurs once a year in the South China Sea, and at the same depth of 1200m, a new system constraint method is adopted-the top of the system is constrained by six degrees of freedom and decreases at a uniform speed. The pros and cons of additional mass on the stability of the BOP, the size of the offset, and the maximum equivalent stress, provide recommendations for the installation process of oil extraction methods.