Abstract: To maximize the combat capability of submarines,and to enhance its speed characteristics and reduce its sailing noise,the flood hole on-and-off device has been widely used in new type submarines. In this paper,a certain type of flood holes is analyzed,where the motion simulation model is established. The optimization design is also carried out on the motion mechanism with the optimization design function provided by ADAMS. The result shows that the required driving force for the whole structure is reduced significantly. Meanwhile,since the installation errors may appear on the device when assembled on an actual submarine,a secondary optimization design under certain added constraints is conducted. The corresponding result reveals significant improvement in dynamic performance. In brief,the proposed method can be applied to the future optimization design and the institutional foundation enhancement.