The open-sea terminals are in bad natural conditions which cause mooring line failure and sudden vessel movement. Such an accident can lead to costly damage to cargo handling equipment or other nearby vessels and structures, oil pollution. Therefore, this paper proposes a multi-criteria fuzzy optimization model of open-sea oil terminal's layout. The model is to improve port operations and safety by considering line tensions and theirs non-uniformity coefficients, and vessel motions as criteria. Finally, its application of optimizing the layout of open-sea oil terminal is also given, and the results show that the proposed model is applicable in structural optimization.