Abstract: An omnidirectional incident electromagnetic environment was constructed, so that the polarization angle of the incident electromagnetic wave was within the range of 0,π/2, the incident angle was within the range of 0,2π, and the azimuth angle was randomly distributed within the range of 0,π/2. The incident points of the electromagnetic wave are randomly distributed on a unit sphere centered on the cable. We focused on studying the similarities and differences between the Agrawal model and the Vance model in solving the field line coupling problem, and analyzed the effects of parameters such as cable height, length, radius, and termination resistance on the field line coupling results. The results show that the response waveforms of the Agrawal model and the Vance model to omnidirectional electromagnetic waves are generally consistent, but there is a certain deviation in the response amplitude. This is mainly due to the presence of a lumped source caused by the vertical electric field in the Agrawal model. When the lumped source is ignored, the two models can obtain the same response results. The response current on the cable increases with the height, length, and radius of the cable above the ground. The peak value of the response current of different terminal resistors decreases with the increase of terminal load.