As a strong electromagnetic pulse becomes more and more dangerous to unmanned aerial vehicle (UAV), it is urgent to study the coupling effect of strong electromagnetic pulse on UAV. Based on the electromagnetic topology theory, this paper analyzes the coupling principle of UAV model, and establishes 3D model and cable distribution model of UAV. The field path co-simulation method was used to obtain the distribution of the internal field intensity of the UAV and the internal current of the cable under 0-12GHZ strong electromagnetic pulse interference, providing guidance for the electromagnetic pulse protection of the UAV.