Abstract: The plates of ships are divided into two types according to the different load that the plate endured, that is the plate of plane stress which enduring the load of middle plane, and the bending plate which endures the load of that perpendicular to middle plane. Based on this classification, the orthotropic plate in structure can be transformed into that in material with different methods, which means the stiffeners are to be converted into the plates added on by a certain method,and in further, it simulates the orthotropic plate in material with finite element software. However,this transformation is not completely equivalent, therefore some correction methods paesented for some parameters to make the parameters concerned in the engineering field equal. By comparing the results obtained from the finite element software, it shows that the perpendicular orthot ropic plate is practicable in some engineering field, and the results of the work has some referential values to the related research and engineering calculation.