Determining the near-surface electromagnetic environment of HEMP is the basis for studying the HEMP effect of near-surface electronic devices.Since the ground has a reflection effect on the electromagnetic field, the electromagnetic environment near the ground is quite different from the electromagnetic pulse environment in free space.By analyzing the propagation characteristics of near-surface HEMP and the difference of soil electrical parameters, an inhomogeneous media influence model was established.The modified Fresnel reflection coefficient was used to calculate the model, the accuracy and simplicity of CST numerical simulation method were validated, and a simulation was made to the near-surface complex electromagnetic environment.The results show that:1) The waveform, ground height, upper layer thickness and incident angle have obvious influence on HEMP;and 2) Inhomogeneous medium makes the near-surface HEMP electromagnetic pulse environment different from that of the homogeneous medium.The conclusion supplies a basic basis for guiding the near-surface electromagnetic pulse protection.