Abstract: Research on the electromagnetic environment effect of aircraft has received attention in study of complex electromagnetic environment. With the rapid development of computer technology, using numerical simulation technology to obtain the electromagnetic characteristics of vehicle has become an important means to study aircraft electromagnetic environment effects. This paper demonstrated a massively parallel 3D full-wave electromagnetic field simulation program software JEMS-FDTD and its application to electromagnetic characteristics simulation of a transport plane, and obtained the electromagnetic information in pulse irradiation, such as the time andfrequency domain, and near field/far field and electromagnetic distribution. In order to ensure the accuracy of the calculation, a non-uniform and high order FDTD computing technology was used.