Abstract: esh generation is an important pre-process for the finite difference time domain（FDTD） simulation algorithm. Most commercial softwares use triangle pieces to describe model geometry， while the FDTD algorithm must use rectangular cells to achieve the same end； thus， a meshing process is required in order to snip the original model into its FDTD computational region. The traditional origin-searching based meshing technique is low in both efficiency and accuracy. In this article， we detect the interception point between the model and the FDTD grid ray clusters based on the ray tracing technique， which generates the mesh information with high accuracy and efficiency. Furthermore， the multiple direction ray tracing technique is used in order to correctly capture the mesh for some special models. Finally， we apply the proposed method， combined with high-order conformal FDTD simulation algorithm， on an ship platform with aircrafts， whose surface current distribution under a high power EMP incident wave is successfully simulated.