At present, the domestic cruise ship design is still at an initial stage. In order to break through the domestic design bottleneck of special structures such as the atrium of cruise ship, a 50 000 t cruise ship project is taken for example to make the structure design of the atrium spanning three decks amidships. In the case of no mature standard reference, based on the characteristics of atrium layout, the main points of atrium structure design are proposed, and the atrium structure design scheme of cruise ship is formed in combination with instances. The finite element simulation calculation is made to organize and form the atrium structure strength check guidance of cruise ship. According to the check results, the atrium structure design optimization scheme of cruise ship is given, which can greatly reduce the atrium structure stress level and provide guidance for the atrium structure design and strength check of similar ships.