With the continuous construction of the UHV power grid in China, the electromagnetic scattering of electromagnetic waves from random rough surfaces will have a certain impact on the passive interference of high-voltage transmission lines. To solve the problem of solving the propagation law of electromagnetic scattering in the electromagnetic interference of high-voltage transmission lines to radio stations, this paper is based on the approximation method and moment method of electromagnetic scattering, This paper explores the influence of lossless rough surface and lossy rough surface on the passive interference of high-voltage tower line, focusing on the influence of sea level and dielectric constant of seawater on the electromagnetic scattering characteristics of the target under the sea background, and obtains the general law.