The grounding network plays a vital role as an essential discharge channel for electrical equipment, ensuring the smooth operation of the power network. Any faults within the grounding network pose a significant threat to the safety of the power system, emphasizing the utmost importance of fault detection and status evaluation. Based on the fundamental working principle of transient electromagnetic method, a forward calculation model is developed using finite element method for fault detection in grounding networks. The typical characteristics of transient electromagnetic signals are analyzed based on ring grids. The impact of transient electromagnetic emission, the operational state of the receiving coil, and the grounding network (including transmitting current amplitude, transition time, measuring height of coil, and coil radius) on induced voltage reception is defined. The results demonstrate that utilizing a pulse current with an amplitude of 50 A at a transition time of 5 μs from a transmitting coil with a radius of 0.5 m to obtain an ideal induced voltage signal at a measuring height position of 0.6 m using a receiving coil with a radius of 0.3 m provides theoretical guidance for advancing fault detection technology in grounding networks.