Aluminum sandwich panels are primarily used on luxury cruise liners and speedboats. The lightweight alterative design for the local structure of the superstructure of a common civilian ship is carried out to expand the application scope of aluminum sandwich panels. The structural configuration and the corresponding type of the connection structure are then determined according to the structural characteristics of the sandwich panel. And the mechanical properties of the superstructure before and after the alternative design are compared and analyzed by using the finite element software ABAQUS. The results show that the superstructure of aluminum sandwich panel have better mechanical properties with the reduced structure weight. It can provide reference for the promotion and application of aluminum sandwich panels in the future.