The signal of transient electromagnetic observation is influenced by the excitation source mode, geological body conductivity, coupling mode between the emitting part and the receiving part, damping characteristic of the receiving coil, and the capacitive and inductive parameters of the receiving coil, among other factors. When studying the laws of transient electromagnetic response, it is generally assumed that the above system parameters are ideal and not considered, which makes it difficult for the actual transient electromagnetic signal to match the theoretical calculated value. This study proposed a model of transient electromagnetics, set up an equivalent circuit of the transient electromagnetic emitting system, geological body, and receiving system, and developed a basic process simulation system for ground central loop source TEM by establishing the mutual inductance and coupling relationship between the emitting source, geological body, and receiving coil. The system fully considers the parameters of the emitting unit (the inductance and distributed capacitance of the emitting coil and the switching time) and the parameters of the receiving unit (internal resistance, matching resistance, inductance, and distributed capacitance), and by arbitrarily changing a single parameter or multiple parameters, the influence of these parameters on the transient electromagnetic attenuation curve can be studied. The output results of the model are compared with the theoretical output results obtained from the receiving coil control equation to complete the accuracy verification. Based on this, the effects of the switching time, emitting coil inductance and capacitance, receiving coil damping factor, and impedance characteristics on the transient electromagnetic receiving signal are studied. The results indicate that reducing the turn-off time, loop inductance, and capacitance on the transmission end helps improve signal quality. On the receiving end, the impedance characteristics of the receiving coil are the main factor determining the received signal. It was concluded that the signal quality is better when the receiving coil resistance is slightly underdamped or critically damped. Finally, the transient electromagnetic signal is simulated by setting the instrument's measured parameters, and it is compared with the actual data of the instrument. The developed model can be used for calibration of the measured parameters and signals of the instrument, as well as forward design of the instrument. The comparison with measured results further verified the reliability of the developed simulation system for TEM, contributing to the advancement of efficient parameter research and instrument optimization in TEM applications.