Objectives  The dynamic stability of large ocean-going passenger vessel is of great important to ensuring the safety of a large number of passengers. Thus, it is necessary to carry out vulnerability assessment and optimization for typical failure modes.

  Methods  This study adopts the assessment methods and criteria of parametric rolling, pure loss of stability and excessive acceleration developed by the international maritime organization's (IMO) second generation intact stability criteria. For the first time, the vulnerability assessment of dynamic stability failure modes is conducted for the design scheme project of a large ocean-going passenger vessel. In order to fulfill the requirements of this project, an optimization scheme is studied and proposed for the design from a practical point of view.

  Results  The assessment results show that the original ship design scheme is not vulnerable to the evaluated dynamic stability failure modes except the pure loss of stability failure mode without considering the speed limit, that means the safety level can meet the requirement. However, the scheme cannot fulfill the requirements of pure loss of stability criterion, when the service speed needs to be increased to 24.8 kn. By slightly adjusting the design of hull and windows to improve the reserve buoyancy, the safety level of pure loss of stability failure mode can be effectively increased, and the service speed limit can be eliminated.

  Conclusions  The design scheme of large ocean-going passenger vessel has a high safety margin of dynamic stability, which can fully ensure the dynamic stability and safety of large passenger vessels sailing in serious sea conditions.