The primary distinction between deepwater drilling and shallow-water drilling lies in the greater water depth, necessitating the use of long risers to ensure drilling operations. Additionally, as water depth increases, the mechanical properties of shallow seabed soils change. Under the influence of factors such as drilling vessel drift and ocean current impacts, subsea wellheads face instability risks. Existing mechanical stability calculation models for wellheads often employ deterministic parameters. However, the complex environment of deepwater drilling introduces numerous uncertainties, reducing the accuracy and reliability of these models. Therefore, based on the study of mechanical stability calculation models for deepwater subsea wellheads, it is essential to analyze sensitive and uncertain factors and establish a risk assessment methodology that accounts for uncertainties. This approach provides technical support for quantitatively evaluating and mitigating instability risks in deepwater subsea wellheads.