Substation is place where strong current and weak current of power system concentrate most, and its electromagnetic environment is complex. Power frequency current, over-current caused by lightning, operating current and the impulse current and so on , will cause a variety of electromagnetic disturbance, and quipments and buildings in substation can block electromagnetic radiation to some degree, and effects of refraction and reflection make electromagnetic interference situation more complex. So, electromagnetic environment of substation, effects of objects in the substation on the propagation of electromagnetic radiation worth deep researches. By means of FEKO, this paper sets electric dipole made up of a length of wire as interference source, simulate and analyze over radiation situation of electric dipole in free space. Set interference source near a simplified transformer model, simulate and analyze filed intensity of transformer nearby. Next, set interference source in different places of simplified substation model, and simulate by FEKO, and obtain the electric field distribution graphs of interference source in horizontal plane of different height, and analyze interference result of substation by graphs.